R Markdown

Abstract: The Covid pandemic has affected the global world. One of the major affects were seen in workplaces. Many companies have since moved either partially or fully remote; especially the software industry. Using our survey based dataset we will be conducting analysis on Covid19 and it’s affects on the software industry.

Dataset:

   A data frame with 1512 observations on 15 variables
  [, IV1]  Thinking about your current job, how much of your work time have you 
           spent working remotely this year?  If you work a 5 day week, each day 
           of remote working equals 20% of your time.  
  [, A1]   Does your employer have a policy that workers must be at the employer’s
           workplace some of the time?  
  [, IV2]  How much of your work time does your employer’s policy require you to 
           be at their workplace?  If you work a 5 day week, 1 day equals 20% of 
           your work time.  
  [, A2]   Imagine that COVID-19 is cured or eradicated.    How likely would you 
           consider the following statements?   - I would have more choice about 
           whether I work remotely
  [, IV3]  Think about your experience this year. On a day when you attend your 
           employer's workplace, how many hours would you spend doing the 
           following activities?   For example, a response of ‘1’ means 1 hour.  A
           response of ‘0.5’ means half an hour.   Your responses should add to 24
           hours. - Preparing for work and commuting
  [, IV4]  Think about your experience this year. On a day when you attend your 
           employer's workplace, how many hours would you spend doing the 
           following activities?   For example, a response of ‘1’ means 1 hour.  A
           response of ‘0.5’ means half an hour.   Your responses should add to 24
           hours. - Working
  [, IV5]  Think about your experience this year. On a day when you attend your 
           employer's workplace, how many hours would you spend doing the 
           following activities?   For example, a response of ‘1’ means 1 hour.  A
           response of ‘0.5’ means half an hour.   Your responses should add to 24
           hours. - Caring and domestic responsibilities
  [, IV6]  Think about your experience this year. On a day when you attend your 
           employer's workplace, how many hours would you spend doing the 
           following activities?   For example, a response of ‘1’ means 1 hour.  A
           response of ‘0.5’ means half an hour.   Your responses should add to 24
           hours. - Personal and family time
  [, IV7]  Think about your experience this year. On a day when you attend your 
           employer's workplace, how many hours would you spend doing the 
           following activities?   For example, a response of ‘1’ means 1 hour.  A
           response of ‘0.5’ means half an hour.   Your responses should add to 24
           hours. - Sleep
  [, IV8]  Think about your experience this year. On a day when you work remotely,
           how many hours would you spend doing the following activities?  For 
           example, a response of ‘1’ means 1 hour.  A response of ‘0.5’ means 
           half an hour.   Your responses should add to 24 hours.   - Preparing 
           for work and commuting
  [, IV9]  Think about your experience this year. On a day when you work remotely,
           how many hours would you spend doing the following activities?  For 
           example, a response of ‘1’ means 1 hour.  A response of ‘0.5’ means 
           half an hour.   Your responses should add to 24 hours.   - Working
  [, IV10] Think about your experience this year. On a day when you work remotely,
           how many hours would you spend doing the following activities?  For 
           example, a response of ‘1’ means 1 hour.  A response of ‘0.5’ means 
           half an hour.   Your responses should add to 24 hours.   - Caring and 
           domestic responsibilities
  [, IV11] Think about your experience this year. On a day when you work remotely,
           how many hours would you spend doing the following activities?  For 
           example, a response of ‘1’ means 1 hour.  A response of ‘0.5’ means 
           half an hour.   Your responses should add to 24 hours.   - Personal and
           family time
  [, IV12] Think about your experience this year. On a day when you work remotely,
           how many hours would you spend doing the following activities?  For 
           example, a response of ‘1’ means 1 hour.  A response of ‘0.5’ means 
           half an hour.   Your responses should add to 24 hours. - Sleep
  [, D1]   This question is about your productivity. Productivity means what you 
           produce for each hour that you work. It includes the amount of work you
           achieve each hour, and the quality of your work each hour.    Please 
           compare your productivity when you work remotely to when you work at 
           your employer’s workplace. Roughly how productive are you, each hour, 
           when you work remotely?
  
         

Hypothesis

  - Null hypothesis (H0): Remote work HAS NOT affected the software industry 
                          during covid 19 pandemic 
  - Alternative hypothesis (Ha): Remote work HAS affected the software industry 
                                 during covid 19 pandemic

Independent Variables

  - The elements (columns/variables) that are used to predict the dependent variable are 
    known as independent variables. A single dependent 
    variable has utilized in all cases, and a number of independent variables are 
    combined with it in order to predict the dependent variable based on changes 
    in the independent variables. For the developed hypothesis, the IV is the 
    IV9. However,depending on the hypothesis, the possible independent variables 
    are IV1, IV2, IV3, IV4, IV5, IV6, IV7, IV8, IV10, IV11 and IV12. 

Dependent Variables

  - The primary factor (Column/variable) predicted by regression is called 
    the dependent variable. In this case, the dataset's dependent variable is the 
    D1.

Importing Dataset

covidData <- read.csv("C:/Users/billy/OneDrive/Documents/ANLY 500/covidIT_data.csv", check.names = F)
str(covidData)
## 'data.frame':    1512 obs. of  15 variables:
##  $ IV1 : num  0.5 0.1 0.9 0.4 1 0.5 0.8 1 0.5 0.9 ...
##  $ A1  : chr  "Yes" "Yes" "Yes" "Yes" ...
##  $ IV2 : num  0.4 1 0.2 0.5 0 0 0.2 0 0 0 ...
##  $ A2  : chr  "Somewhat likely" "Neither unlikely or likely" "Very likely" "Somewhat likely" ...
##  $ IV3 : num  2 1.5 3 1 5 3 2 1.5 1 1.5 ...
##  $ IV4 : num  6 8 8 8 8 8 8 8.5 8 8 ...
##  $ IV5 : num  1 2 1 6 2 2 3 0.5 5 0 ...
##  $ IV6 : num  7 6 4 3 3 3 3 5.5 2 7.5 ...
##  $ IV7 : num  8 6.5 8 6 6 8 8 8 8 7 ...
##  $ IV8 : num  0 0 1 1 NA 2 1 0.5 1 0.5 ...
##  $ IV9 : num  8 10 8 8 9 8 8 9 7 8 ...
##  $ IV10: num  1 4 2 4 3 4 3 0.5 5 0 ...
##  $ IV11: num  7 4 5 4 4 2 4 5 3 8.5 ...
##  $ IV12: num  8 6 8 7 8 8 8 9 8 7 ...
##  $ D1  : num  0.5 0.5 0 0.5 0.2 0.2 0.1 0.2 -0.5 0.5 ...

Librarys and functions

#install.packages("readr")
library(readr)
#install.packages("ggplot2")
library(ggplot2)
#install.packages("psych")
library (psych)
## 
## Attaching package: 'psych'
## The following objects are masked from 'package:ggplot2':
## 
##     %+%, alpha
#install.packages("mice", repos = "https://cran.us.r-project.org/")
library(mice)
## 
## Attaching package: 'mice'
## The following object is masked from 'package:stats':
## 
##     filter
## The following objects are masked from 'package:base':
## 
##     cbind, rbind
cleanup <- theme(panel.grid.major = element_blank(),
                 panel.grid.minor = element_blank(),
                 panel.background = element_blank(),
                 axis.line.x = element_line(color = 'black'),
                 axis.line.y = element_line(color = 'black'),
                 legend.key = element_rect(fill = 'white'), 
                 text = element_text(size = 10))

The structure and preview of the data

str(covidData)
## 'data.frame':    1512 obs. of  15 variables:
##  $ IV1 : num  0.5 0.1 0.9 0.4 1 0.5 0.8 1 0.5 0.9 ...
##  $ A1  : chr  "Yes" "Yes" "Yes" "Yes" ...
##  $ IV2 : num  0.4 1 0.2 0.5 0 0 0.2 0 0 0 ...
##  $ A2  : chr  "Somewhat likely" "Neither unlikely or likely" "Very likely" "Somewhat likely" ...
##  $ IV3 : num  2 1.5 3 1 5 3 2 1.5 1 1.5 ...
##  $ IV4 : num  6 8 8 8 8 8 8 8.5 8 8 ...
##  $ IV5 : num  1 2 1 6 2 2 3 0.5 5 0 ...
##  $ IV6 : num  7 6 4 3 3 3 3 5.5 2 7.5 ...
##  $ IV7 : num  8 6.5 8 6 6 8 8 8 8 7 ...
##  $ IV8 : num  0 0 1 1 NA 2 1 0.5 1 0.5 ...
##  $ IV9 : num  8 10 8 8 9 8 8 9 7 8 ...
##  $ IV10: num  1 4 2 4 3 4 3 0.5 5 0 ...
##  $ IV11: num  7 4 5 4 4 2 4 5 3 8.5 ...
##  $ IV12: num  8 6 8 7 8 8 8 9 8 7 ...
##  $ D1  : num  0.5 0.5 0 0.5 0.2 0.2 0.1 0.2 -0.5 0.5 ...
head(covidData)
tail(covidData)
dim(covidData)
## [1] 1512   15
names(covidData)
##  [1] "IV1"  "A1"   "IV2"  "A2"   "IV3"  "IV4"  "IV5"  "IV6"  "IV7"  "IV8" 
## [11] "IV9"  "IV10" "IV11" "IV12" "D1"

Data Screening/Cleanup

### Data Screening
## Converting character variables and Checking errors
summary(covidData)
##       IV1              A1                 IV2             A2           
##  Min.   :0.0000   Length:1512        Min.   :0.000   Length:1512       
##  1st Qu.:0.2000   Class :character   1st Qu.:0.000   Class :character  
##  Median :0.5000   Mode  :character   Median :0.100   Mode  :character  
##  Mean   :0.4969                      Mean   :0.264                     
##  3rd Qu.:0.8000                      3rd Qu.:0.500                     
##  Max.   :1.0000                      Max.   :1.000                     
##                                                                        
##       IV3              IV4              IV5              IV6        
##  Min.   : 0.000   Min.   : 0.000   Min.   : 0.000   Min.   : 0.000  
##  1st Qu.: 1.000   1st Qu.: 7.000   1st Qu.: 2.000   1st Qu.: 3.000  
##  Median : 2.000   Median : 8.000   Median : 3.000   Median : 4.000  
##  Mean   : 2.246   Mean   : 7.832   Mean   : 2.797   Mean   : 3.855  
##  3rd Qu.: 3.000   3rd Qu.: 8.500   3rd Qu.: 4.000   3rd Qu.: 5.000  
##  Max.   :20.000   Max.   :20.000   Max.   :19.000   Max.   :14.000  
##  NA's   :3        NA's   :3        NA's   :17       NA's   :5       
##       IV7              IV8              IV9             IV10       
##  Min.   : 0.000   Min.   : 0.000   Min.   : 0.00   Min.   : 0.000  
##  1st Qu.: 7.000   1st Qu.: 0.000   1st Qu.: 7.00   1st Qu.: 2.000  
##  Median : 8.000   Median : 0.500   Median : 8.00   Median : 3.000  
##  Mean   : 7.393   Mean   : 1.178   Mean   : 8.11   Mean   : 3.026  
##  3rd Qu.: 8.000   3rd Qu.: 1.000   3rd Qu.: 9.00   3rd Qu.: 4.000  
##  Max.   :20.000   Max.   :24.000   Max.   :24.00   Max.   :17.000  
##  NA's   :12       NA's   :24       NA's   :3       NA's   :18      
##       IV11             IV12              D1         
##  Min.   : 0.000   Min.   : 0.000   Min.   :-0.5000  
##  1st Qu.: 3.000   1st Qu.: 7.000   1st Qu.: 0.0000  
##  Median : 4.000   Median : 8.000   Median : 0.2000  
##  Mean   : 4.335   Mean   : 7.485   Mean   : 0.1737  
##  3rd Qu.: 5.000   3rd Qu.: 8.000   3rd Qu.: 0.4000  
##  Max.   :24.000   Max.   :14.000   Max.   : 0.5000  
##  NA's   :7        NA's   :9
notypos <- covidData
notypos$A1 <- factor(notypos$A1, 
                         labels = c("Yes", "No"))
notypos$A2 <- factor(notypos$A2, 
                         labels = c("Very unlikely", "Very likely", "Neither unlikely or likely", "Somewhat likely", "Somewhat unlikely"))
summary(notypos)
##       IV1           A1           IV2                                 A2     
##  Min.   :0.0000   Yes:552   Min.   :0.000   Very unlikely             :384  
##  1st Qu.:0.2000   No :960   1st Qu.:0.000   Very likely               :455  
##  Median :0.5000             Median :0.100   Neither unlikely or likely:222  
##  Mean   :0.4969             Mean   :0.264   Somewhat likely           :254  
##  3rd Qu.:0.8000             3rd Qu.:0.500   Somewhat unlikely         :197  
##  Max.   :1.0000             Max.   :1.000                                   
##                                                                             
##       IV3              IV4              IV5              IV6        
##  Min.   : 0.000   Min.   : 0.000   Min.   : 0.000   Min.   : 0.000  
##  1st Qu.: 1.000   1st Qu.: 7.000   1st Qu.: 2.000   1st Qu.: 3.000  
##  Median : 2.000   Median : 8.000   Median : 3.000   Median : 4.000  
##  Mean   : 2.246   Mean   : 7.832   Mean   : 2.797   Mean   : 3.855  
##  3rd Qu.: 3.000   3rd Qu.: 8.500   3rd Qu.: 4.000   3rd Qu.: 5.000  
##  Max.   :20.000   Max.   :20.000   Max.   :19.000   Max.   :14.000  
##  NA's   :3        NA's   :3        NA's   :17       NA's   :5       
##       IV7              IV8              IV9             IV10       
##  Min.   : 0.000   Min.   : 0.000   Min.   : 0.00   Min.   : 0.000  
##  1st Qu.: 7.000   1st Qu.: 0.000   1st Qu.: 7.00   1st Qu.: 2.000  
##  Median : 8.000   Median : 0.500   Median : 8.00   Median : 3.000  
##  Mean   : 7.393   Mean   : 1.178   Mean   : 8.11   Mean   : 3.026  
##  3rd Qu.: 8.000   3rd Qu.: 1.000   3rd Qu.: 9.00   3rd Qu.: 4.000  
##  Max.   :20.000   Max.   :24.000   Max.   :24.00   Max.   :17.000  
##  NA's   :12       NA's   :24       NA's   :3       NA's   :18      
##       IV11             IV12              D1         
##  Min.   : 0.000   Min.   : 0.000   Min.   :-0.5000  
##  1st Qu.: 3.000   1st Qu.: 7.000   1st Qu.: 0.0000  
##  Median : 4.000   Median : 8.000   Median : 0.2000  
##  Mean   : 4.335   Mean   : 7.485   Mean   : 0.1737  
##  3rd Qu.: 5.000   3rd Qu.: 8.000   3rd Qu.: 0.4000  
##  Max.   :24.000   Max.   :14.000   Max.   : 0.5000  
##  NA's   :7        NA's   :9
names(notypos)
##  [1] "IV1"  "A1"   "IV2"  "A2"   "IV3"  "IV4"  "IV5"  "IV6"  "IV7"  "IV8" 
## [11] "IV9"  "IV10" "IV11" "IV12" "D1"
apply(notypos[ , -c(2, 4)], 2, mean, na.rm = T)
##       IV1       IV2       IV3       IV4       IV5       IV6       IV7       IV8 
## 0.4968915 0.2639550 2.2457720 7.8318754 2.7971237 3.8546715 7.3933667 1.1781922 
##       IV9      IV10      IV11      IV12        D1 
## 8.1104705 3.0261714 4.3354020 7.4849301 0.1736772
apply(notypos[ , -c(2, 4)], 2, sd, na.rm = T)
##       IV1       IV2       IV3       IV4       IV5       IV6       IV7       IV8 
## 0.3487668 0.3331513 1.6436332 1.9310000 1.6261774 1.7657156 1.5473905 1.9498599 
##       IV9      IV10      IV11      IV12        D1 
## 2.0983928 1.5731061 1.9087719 1.5674942 0.2409066
## Checking missing data
apply(notypos, 2, function(x) { sum(is.na(x))})
##  IV1   A1  IV2   A2  IV3  IV4  IV5  IV6  IV7  IV8  IV9 IV10 IV11 IV12   D1 
##    0    0    0    0    3    3   17    5   12   24    3   18    7    9    0
percentmiss <- function(x){ sum(is.na(x))/length(x) * 100}
missing <- apply(notypos, 1, percentmiss)
table(missing)
## missing
##                0 6.66666666666667 13.3333333333333               20 
##             1458               31               13                1 
## 26.6666666666667               40 46.6666666666667 
##                7                1                1
replace_rows <- subset(notypos, missing <= 25)
noreplace_row <- subset(notypos, missing > 25)
nrow(notypos)
## [1] 1512
nrow(replace_rows)
## [1] 1503
nrow(noreplace_row)
## [1] 9
apply(replace_rows, 2, percentmiss)
##       IV1        A1       IV2        A2       IV3       IV4       IV5       IV6 
## 0.0000000 0.0000000 0.0000000 0.0000000 0.0665336 0.1330672 0.8649368 0.1330672 
##       IV7       IV8       IV9      IV10      IV11      IV12        D1 
## 0.5322688 1.3306720 0.0000000 0.6653360 0.1330672 0.1330672 0.0000000
replace_columns <- replace_rows[ , -c(2,4)]
noreplace_columns <- replace_rows[ , c(2,4)]
temp_no_miss <- mice(replace_columns)
## 
##  iter imp variable
##   1   1  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   1   2  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   1   3  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   1   4  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   1   5  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   2   1  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   2   2  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   2   3  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   2   4  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   2   5  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   3   1  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   3   2  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   3   3  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   3   4  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   3   5  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   4   1  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   4   2  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   4   3  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   4   4  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   4   5  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   5   1  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   5   2  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   5   3  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   5   4  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
##   5   5  IV3  IV4  IV5  IV6  IV7  IV8  IV10  IV11  IV12
## Warning: Number of logged events: 143
nomiss <- complete(temp_no_miss, 1)
dim(notypos)
## [1] 1512   15
dim(nomiss)
## [1] 1503   13
all_colunms <- cbind(noreplace_columns, nomiss)
dim(all_colunms)
## [1] 1503   15
summary(all_colunms)
##    A1                               A2           IV1              IV2        
##  Yes:547   Very unlikely             :380   Min.   :0.0000   Min.   :0.0000  
##  No :956   Very likely               :452   1st Qu.:0.2000   1st Qu.:0.0000  
##            Neither unlikely or likely:221   Median :0.5000   Median :0.1000  
##            Somewhat likely           :254   Mean   :0.4983   Mean   :0.2647  
##            Somewhat unlikely         :196   3rd Qu.:0.8000   3rd Qu.:0.5000  
##                                             Max.   :1.0000   Max.   :1.0000  
##       IV3              IV4              IV5             IV6       
##  Min.   : 0.000   Min.   : 0.000   Min.   : 0.00   Min.   : 0.00  
##  1st Qu.: 1.000   1st Qu.: 7.000   1st Qu.: 2.00   1st Qu.: 3.00  
##  Median : 2.000   Median : 8.000   Median : 2.75   Median : 4.00  
##  Mean   : 2.219   Mean   : 7.833   Mean   : 2.76   Mean   : 3.84  
##  3rd Qu.: 3.000   3rd Qu.: 8.500   3rd Qu.: 4.00   3rd Qu.: 5.00  
##  Max.   :16.000   Max.   :20.000   Max.   :15.00   Max.   :12.50  
##       IV7              IV8              IV9              IV10       
##  Min.   : 0.000   Min.   : 0.000   Min.   : 0.000   Min.   : 0.000  
##  1st Qu.: 7.000   1st Qu.: 0.000   1st Qu.: 7.000   1st Qu.: 2.000  
##  Median : 8.000   Median : 0.500   Median : 8.000   Median : 3.000  
##  Mean   : 7.352   Mean   : 1.131   Mean   : 8.096   Mean   : 2.997  
##  3rd Qu.: 8.000   3rd Qu.: 1.000   3rd Qu.: 9.000   3rd Qu.: 4.000  
##  Max.   :17.000   Max.   :16.000   Max.   :23.000   Max.   :12.000  
##       IV11           IV12              D1         
##  Min.   : 0.0   Min.   : 0.000   Min.   :-0.5000  
##  1st Qu.: 3.0   1st Qu.: 7.000   1st Qu.: 0.0000  
##  Median : 4.0   Median : 8.000   Median : 0.2000  
##  Mean   : 4.3   Mean   : 7.477   Mean   : 0.1733  
##  3rd Qu.: 5.0   3rd Qu.: 8.000   3rd Qu.: 0.4000  
##  Max.   :20.0   Max.   :14.000   Max.   : 0.5000
## Outliers
#leverage
model1 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = all_colunms)
k <- 14 #Number of IV
leverage <- hatvalues(model1)
cutleverage <- (2*k+2) /nrow(all_colunms)
badleverage <- as.numeric(leverage > cutleverage)
table(badleverage)
## badleverage
##    0    1 
## 1398  105
#Cooks
cooks <- cooks.distance(model1)
cutcooks <- 4 / (nrow(all_colunms) - k - 1)
badcooks <- as.numeric(cooks > cutcooks)
table(badcooks)
## badcooks
##    0    1 
## 1431   72
#Mahal
mahal <- mahalanobis(all_colunms[ , -c(1,2)],
                     colMeans(all_colunms[ , -c(1,2)]),
                     cov(all_colunms[ , -c(1,2)]))
cutmahal <- qchisq(1-.001, ncol(all_colunms[ , -c(1,2)]))
badmahal <- as.numeric(mahal > cutmahal)
table(badmahal)
## badmahal
##    0    1 
## 1427   76
## Overall Outliers 
totalout <- badmahal + badleverage + badcooks
table(totalout)
## totalout
##    0    1    2    3 
## 1357   69   47   30
noout <- subset(all_colunms, totalout < 2)

Assumption Checks

## Additivity
str(noout)
## 'data.frame':    1426 obs. of  15 variables:
##  $ A1  : Factor w/ 2 levels "Yes","No": 2 2 2 2 1 1 2 1 2 2 ...
##  $ A2  : Factor w/ 5 levels "Very unlikely",..: 2 1 4 2 2 1 2 1 1 2 ...
##  $ IV1 : num  0.5 0.1 0.9 0.4 1 0.5 0.8 1 0.5 0.9 ...
##  $ IV2 : num  0.4 1 0.2 0.5 0 0 0.2 0 0 0 ...
##  $ IV3 : num  2 1.5 3 1 5 3 2 1.5 1 1.5 ...
##  $ IV4 : num  6 8 8 8 8 8 8 8.5 8 8 ...
##  $ IV5 : num  1 2 1 6 2 2 3 0.5 5 0 ...
##  $ IV6 : num  7 6 4 3 3 3 3 5.5 2 7.5 ...
##  $ IV7 : num  8 6.5 8 6 6 8 8 8 8 7 ...
##  $ IV8 : num  0 0 1 1 0 2 1 0.5 1 0.5 ...
##  $ IV9 : num  8 10 8 8 9 8 8 9 7 8 ...
##  $ IV10: num  1 4 2 4 3 4 3 0.5 5 0 ...
##  $ IV11: num  7 4 5 4 4 2 4 5 3 8.5 ...
##  $ IV12: num  8 6 8 7 8 8 8 9 8 7 ...
##  $ D1  : num  0.5 0.5 0 0.5 0.2 0.2 0.1 0.2 -0.5 0.5 ...
cor(noout[ , -c(1,2)])
##               IV1         IV2         IV3          IV4         IV5          IV6
## IV1   1.000000000 -0.32873025  0.04073436 -0.024248356 -0.07666597 -0.009548454
## IV2  -0.328730251  1.00000000  0.09159735 -0.029309894  0.08032254 -0.058916482
## IV3   0.040734355  0.09159735  1.00000000 -0.228108827 -0.02125173 -0.321536824
## IV4  -0.024248356 -0.02930989 -0.22810883  1.000000000 -0.36423075 -0.392977336
## IV5  -0.076665967  0.08032254 -0.02125173 -0.364230748  1.00000000 -0.295318349
## IV6  -0.009548454 -0.05891648 -0.32153682 -0.392977336 -0.29531835  1.000000000
## IV7   0.088697493 -0.07844387 -0.35374330 -0.097167666 -0.28043129 -0.119094084
## IV8  -0.135077423  0.13502179  0.49626394 -0.321775441  0.18329676 -0.052438713
## IV9   0.049145206 -0.05164419 -0.12236020  0.733002948 -0.29388327 -0.318752046
## IV10 -0.093415587  0.06134702  0.02712966 -0.284174359  0.71161348 -0.195875141
## IV11  0.055751109 -0.06206494 -0.13565702 -0.262357074 -0.25811046  0.634042739
## IV12  0.112135969 -0.06570106 -0.23664803  0.002034401 -0.24375595 -0.109084738
## D1    0.163612758  0.01927080  0.10576987 -0.100859612  0.09222619 -0.067007677
##               IV7         IV8          IV9        IV10        IV11         IV12
## IV1   0.088697493 -0.13507742  0.049145206 -0.09341559  0.05575111  0.112135969
## IV2  -0.078443870  0.13502179 -0.051644186  0.06134702 -0.06206494 -0.065701057
## IV3  -0.353743297  0.49626394 -0.122360203  0.02712966 -0.13565702 -0.236648034
## IV4  -0.097167666 -0.32177544  0.733002948 -0.28417436 -0.26235707  0.002034401
## IV5  -0.280431290  0.18329676 -0.293883272  0.71161348 -0.25811046 -0.243755946
## IV6  -0.119094084 -0.05243871 -0.318752046 -0.19587514  0.63404274 -0.109084738
## IV7   1.000000000 -0.27386097 -0.048449265 -0.23262579 -0.05077909  0.686708693
## IV8  -0.273860970  1.00000000 -0.333811883  0.07246651 -0.25601441 -0.399535481
## IV9  -0.048449265 -0.33381188  1.000000000 -0.33965751 -0.41750130 -0.089080647
## IV10 -0.232625789  0.07246651 -0.339657515  1.00000000 -0.31644775 -0.297433574
## IV11 -0.050779087 -0.25601441 -0.417501299 -0.31644775  1.00000000 -0.088610121
## IV12  0.686708693 -0.39953548 -0.089080647 -0.29743357 -0.08861012  1.000000000
## D1   -0.004600325  0.06469410 -0.001335388  0.03644695 -0.07442951 -0.013655250
##                D1
## IV1   0.163612758
## IV2   0.019270800
## IV3   0.105769873
## IV4  -0.100859612
## IV5   0.092226185
## IV6  -0.067007677
## IV7  -0.004600325
## IV8   0.064694096
## IV9  -0.001335388
## IV10  0.036446949
## IV11 -0.074429506
## IV12 -0.013655250
## D1    1.000000000
#install.packages("corrplot")
library(corrplot)
## corrplot 0.92 loaded
corrplot(cor(noout[ , -c(1,2)]))

# We have met the assumption of additivity.

## Linearity
random <- rchisq(nrow(noout), 7)
fake <- lm(random ~ .,
           data = noout)
standardized <- rstudent(fake)
fitvaules <- scale(fake$fitted.values)
{qqnorm(standardized)
  abline(0,1)}

plot(fake, 2)

# We have not met the assumption for linearity as the plot shows above since it's not between -2 and 2 and the tails of the plot are fat.

## Normality
#install.packages("moments")
library(moments)
skewness(noout[ , -c(1,2)])
##        IV1        IV2        IV3        IV4        IV5        IV6        IV7 
##  0.1125337  0.9689997  1.1586409 -0.5227377  0.4864770  0.5846907 -0.4986082 
##        IV8        IV9       IV10       IV11       IV12         D1 
##  2.2056853 -0.2812643  0.4816787  0.4451744 -0.7716670 -0.3732701
kurtosis(noout[ , -c(1,2)]) - 3
##        IV1        IV2        IV3        IV4        IV5        IV6        IV7 
## -1.4148330 -0.3945146  2.1224644  2.4926685  0.2015405  0.6450057  2.4610933 
##        IV8        IV9       IV10       IV11       IV12         D1 
##  5.0260046  1.8336889  0.6846064  0.7579440  3.4185970 -0.4188437
hist(standardized, breaks=15)

length(standardized)
## [1] 1426
# We have met the assumption for normality as it is close to a normal distribution with a bit of a right skew.

## Homogeneity/Homoscedasticity
{plot(fitvaules, standardized)
  abline(0,0)
  abline(v = 0)}

# The assumption for Homogeneity and Homoscedasticity have been met as the plot shown below is equally distributed top to bottom and left to right respectively.

Exploratory Data Anaysis: Frequency Distribution of Data

# Frequency table and Histogram for IV3: Time spent preparing for work and commuting - workplace
fIV3 = table (noout$IV3)
fIV3
## 
##    0  0.2 0.25  0.4  0.5  0.7    1 1.25  1.5 1.75    2 2.12  2.5    3  3.5    4 
##   50    2    5    1   54    1  333    2   92    1  397    1   56  230   20   94 
##  4.5    5    6    7    8    9 
##    1   52   24    3    6    1
histIV3 <- ggplot(noout, aes(x = IV3))
histIV3 + 
  geom_histogram(binwidth = 0.4, 
                 color = "black", 
                 fill = "grey") + 
  xlab("Preparing for work and commuting") +
  ylab("Frequency") + 
  ggtitle("Time spent preparing for work and commuting - Workplace") +
  cleanup

describe(noout$IV3)
# Frequency table and Histogram for IV4: Time spent working - Workplace 
fIV4 = table (noout$IV4)
fIV4
## 
##  1.5    2    3    4    5    6  6.5 6.75    7  7.5  7.6    8  8.5  8.6    9  9.5 
##    1    9   12   34   47   85    2    1  172   62    4  610   46    1  169   10 
##  9.7   10 10.5   11 11.5   12   13   14 
##    1  109    3   17    2   25    2    2
histIV4 <- ggplot(noout, aes(x = IV4))
histIV4 + 
  geom_histogram(binwidth = 0.4, 
                 color = "black", 
                 fill = "grey") + 
  xlab("Working") +
  ylab("Frequency") + 
  ggtitle("Time spent Working - Workplace") +
  cleanup

describe(noout$IV4)
# Frequency table and Histogram for IV5: Time spent Caring and domestic responsibilities - Workplace
fIV5 = table (noout$IV5)
fIV5
## 
##      0    0.5      1    1.5      2    2.3    2.4    2.5   2.75 2.8999      3 
##     59      9    179     30    415      1      1     24      2      1    320 
##    3.5    3.6      4    4.5      5    5.5      6    6.5      7      8 
##     18      1    205     10    101      2     34      1     11      2
histIV5 <- ggplot(covidData, aes(x = IV5))
histIV5 + 
  geom_histogram(binwidth = 0.4, 
                 color = "black", 
                 fill = "grey") + 
  xlab("Caring and domestic responsibilities") +
  ylab("Frequency") + 
  ggtitle("Time spent Caring and domestic responsibilities - Workplace") +
  cleanup
## Warning: Removed 17 rows containing non-finite values (`stat_bin()`).

describe(noout$IV5)
# Frequency table and Histogram for IV6: Time spent Personal and family time - Workplace
fIV6 = table (noout$IV6)
fIV6
## 
##    0  0.5    1  1.5    2 2.25  2.5 2.75    3  3.5 3.75    4  4.5    5  5.3  5.5 
##    6    3   57   12  224    1   22    1  292   39    1  338   22  208    1   15 
## 5.75  5.8    6  6.5    7  7.5    8    9   10   11 
##    1    1   98   11   31    9   24    5    3    1
histIV6 <- ggplot(noout, aes(x = IV6))
histIV6 + 
  geom_histogram(binwidth = 0.4, 
                 color = "black", 
                 fill = "grey") + 
  xlab("Personal and family time - Workplace") +
  ylab("Frequency") + 
  ggtitle("Time spent Personal and family time - Workplace") +
  cleanup

describe(noout$IV6)
# Frequency table and Histogram for IV7: Time spent Sleep - Workplace
fIV7 = table (noout$IV7)
fIV7
## 
##    2    3    4    5  5.5    6  6.5    7 7.25  7.5  7.7 7.75  7.8    8  8.5 8.75 
##    3    6   25   37    3  167   16  339    1   39    1    1    1  620   12    1 
##  8.9    9  9.5  9.9   10 10.5   11   12 
##    1   96    3    1   40    1    6    6
histIV7 <- ggplot(noout, aes(x = IV7))
histIV7 + 
  geom_histogram(binwidth = 0.4, 
                 color = "black", 
                 fill = "grey") + 
  xlab("Sleep") +
  ylab("Frequency") + 
  ggtitle("Time spent Sleep - Workplace") +
  cleanup

describe(noout$IV7)
# Frequency table and Histogram for IV8: Time spent preparing for work and commuting - Remote
fIV8 = table (noout$IV8)
fIV8
## 
##    0  0.1  0.2 0.25  0.3  0.4  0.5    1  1.5    2  2.5    3  3.5    4    5    6 
##  544    2    2    6    2    1  296  282    9  112    4   49    1   48   36   22 
##    7    8    9 
##    5    4    1
histIV8 <- ggplot(noout, aes(x = IV8))
histIV8 + 
  geom_histogram(binwidth = 0.4, 
                 color = "black", 
                 fill = "grey") + 
  xlab("Preparing for work and commuting") +
  ylab("Frequency") + 
  ggtitle("Time spent preparing for work and commuting - Remote") +
  cleanup

describe(noout$IV8)
# Frequency table and Histogram for IV9: Time spent working - Remote
fIV9 = table (noout$IV9)
fIV9
## 
##    1    2  2.5    3    4    5    6  6.5    7  7.5  7.6    8  8.5 8.75    9  9.5 
##    2    6    1   13   31   47   91    2  145   47    1  493   41    2  207   18 
## 9.75   10 10.5   11 11.5   12   13   14   15   16 
##    1  190    6   20    1   52    4    2    2    1
histIV9 <- ggplot(noout, aes(x = IV9))
histIV9 + 
  geom_histogram(binwidth = 0.4, 
                 color = "black", 
                 fill = "grey") + 
  xlab("Working") +
  ylab("Frequency") + 
  ggtitle("Time spent working - Remote") +
  cleanup

describe(noout$IV9)
# Frequency table and Histogram for IV10: Time spent Caring and domestic responsibilities - Remote
fIV10 = table (noout$IV10)
fIV10
## 
##    0  0.5    1  1.5    2  2.5    3  3.5  3.7 3.75    4 4.25  4.5    5  5.5    6 
##   40    5  134   33  352   35  350   15    1    1  272    1   13  118    4   33 
##  6.5    7    8   10 
##    1   10    7    1
histIV10 <- ggplot(noout, aes(x = IV10))
histIV10 + 
  geom_histogram(binwidth = 0.4, 
                 color = "black", 
                 fill = "grey") + 
  xlab("Caring and domestic responsibilities") +
  ylab("Frequency") + 
  ggtitle("Time spent Caring and domestic responsibilities - Remote") +
  cleanup

describe(noout$IV10)
# Frequency table and Histogram for IV11: Time spent Personal and family time - Remote
fIV11 = table (noout$IV11)
fIV11
## 
##    0    1  1.5    2  2.5    3  3.5  3.6    4 4.25  4.5 4.69  4.9    5 5.25 5.39 
##    9   27    9  146   11  226   36    1  325    2   54    1    1  246    3    1 
##  5.5  5.8    6  6.5 6.75    7  7.5    8  8.5    9  9.5   10   11   12 
##   41    2  149   23    1   48   10   34    7    4    2    3    3    1
histIV11 <- ggplot(noout, aes(x = IV11))
histIV11 + 
  geom_histogram(binwidth = 0.4, 
                 color = "black", 
                 fill = "grey") + 
  xlab("Personal and family time") +
  ylab("Frequency") + 
  ggtitle("Time spent Personal and family time - Remote") +
  cleanup

describe(noout$IV11)
# Frequency table and Histogram for IV12: Time spent Sleep - Remote
fIV12 = table (noout$IV12)
fIV12
## 
##    0    2    3    4    5  5.5    6  6.5    7  7.5 7.75    8  8.5    9  9.4  9.5 
##    1    5    8   30   35    1  123   12  297   39    1  651   20  120    1    7 
##   10   11   12   13 
##   63    3    8    1
histIV12 <- ggplot(noout, aes(x = IV12))
histIV12 + 
  geom_histogram(binwidth = 0.4, 
                 color = "black", 
                 fill = "grey") + 
  xlab("Sleep") +
  ylab("Frequency") + 
  ggtitle("Time spent Sleep - Remote") +
  cleanup

describe(noout$IV12)

Comparison of employee’s productivity when working remotely vs when working at employer’s workplace (IV4 vs IV9)

scatter <- ggplot(noout, aes(IV4, IV9))
scatter +
  geom_point() +
  geom_smooth(method = "lm", color = "blue") + 
  xlab("IV4") +
  ylab("IV9") + 
  ggtitle("Employer’s workplace vs working remotely") + 
  cleanup
## `geom_smooth()` using formula = 'y ~ x'

scatter <- ggplot(noout, aes(D1, IV4))
scatter +
  geom_point() +
  geom_smooth(method = "lm", color = "blue") + 
  xlab("D1") +
  ylab("IV4") + 
  ggtitle("Employee’s productivity when working at Office") + 
  cleanup
## `geom_smooth()` using formula = 'y ~ x'

scatter <- ggplot(noout, aes(D1, IV9))
scatter +
  geom_point() +
  geom_smooth(method = "lm", color = "blue") + 
  xlab("D1") +
  ylab("IV9") + 
  ggtitle("Employee’s productivity when working remotely") + 
  cleanup
## `geom_smooth()` using formula = 'y ~ x'

grouped <- ggplot(noout, aes(IV4, IV9, color = D1))
grouped +
  geom_point() +
  geom_smooth(method = "lm", color = "red") +
  xlab("IV4") +
  ylab("IV9") + 
  ggtitle("Employee’s productivity when working remotely Vs when working at 
          Office") + 
  cleanup
## `geom_smooth()` using formula = 'y ~ x'

Method: Stepwise Regression

modelStep <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep1 <- lm(D1 ~ A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep2 <- lm(D1 ~ A1 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep3 <- lm(D1 ~ A1 + A2 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep4 <- lm(D1 ~ A1 + A2 + IV1 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep5 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep6 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV5 + IV6 + IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep7 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV6 + IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep8 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep9 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep10 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV9 + IV10 + IV11 + IV12, data = noout)
modelStep11 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep12 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV9 + IV11 + IV12, data = noout)
modelStep13 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV9 + IV10 + IV12, data = noout)
modelStep14 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV9 + IV10 + IV11, data = noout)
summary(modelStep7)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV6 + IV7 + 
##     IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88726 -0.15633  0.00522  0.17830  0.45311 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   54.632996 395.165734   0.138 0.890060    
## A1No                           0.019437   0.016361   1.188 0.235022    
## A2Very likely                  0.057128   0.016779   3.405 0.000681 ***
## A2Neither unlikely or likely  -0.005381   0.020420  -0.264 0.792202    
## A2Somewhat likely              0.069245   0.019727   3.510 0.000462 ***
## A2Somewhat unlikely            0.007309   0.022146   0.330 0.741405    
## IV1                            0.104501   0.020113   5.196 2.34e-07 ***
## IV2                            0.040246   0.024176   1.665 0.096192 .  
## IV3                           -0.003271   0.007669  -0.427 0.669749    
## IV4                           -0.036482   0.007707  -4.733 2.43e-06 ***
## IV6                           -0.017161   0.007204  -2.382 0.017347 *  
## IV7                           -0.011108   0.008718  -1.274 0.202847    
## IV8                           -2.258337  16.465293  -0.137 0.890926    
## IV9                           -2.242814  16.465191  -0.136 0.891670    
## IV10                          -2.263796  16.465229  -0.137 0.890664    
## IV11                          -2.262543  16.465295  -0.137 0.890724    
## IV12                          -2.260375  16.465238  -0.137 0.890828    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07967,    Adjusted R-squared:  0.06922 
## F-statistic: 7.623 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07967, Adjusted R-squared:  0.06922 
summary(modelStep6)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV5 + IV6 + IV7 + 
##     IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88724 -0.15634  0.00521  0.17830  0.45307 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   53.744028 395.167050   0.136 0.891838    
## A1No                           0.019443   0.016361   1.188 0.234884    
## A2Very likely                  0.057131   0.016779   3.405 0.000680 ***
## A2Neither unlikely or likely  -0.005381   0.020420  -0.264 0.792197    
## A2Somewhat likely              0.069246   0.019727   3.510 0.000462 ***
## A2Somewhat unlikely            0.007320   0.022146   0.331 0.741053    
## IV1                            0.104503   0.020113   5.196 2.34e-07 ***
## IV2                            0.040241   0.024176   1.664 0.096236 .  
## IV3                            0.033203   0.007404   4.485 7.90e-06 ***
## IV5                            0.036473   0.007707   4.732 2.44e-06 ***
## IV6                            0.019317   0.006707   2.880 0.004037 ** 
## IV7                            0.025367   0.008361   3.034 0.002456 ** 
## IV8                           -2.257773  16.465344  -0.137 0.890953    
## IV9                           -2.242254  16.465242  -0.136 0.891698    
## IV10                          -2.263231  16.465280  -0.137 0.890691    
## IV11                          -2.261981  16.465346  -0.137 0.890751    
## IV12                          -2.259811  16.465288  -0.137 0.890855    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07966,    Adjusted R-squared:  0.06921 
## F-statistic: 7.622 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07966, Adjusted R-squared:  0.06921 
summary(modelStep5)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV7 + 
##     IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88726 -0.15633  0.00521  0.17830  0.45310 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   54.558832 395.168741   0.138 0.890209    
## A1No                           0.019437   0.016361   1.188 0.235011    
## A2Very likely                  0.057129   0.016779   3.405 0.000681 ***
## A2Neither unlikely or likely  -0.005381   0.020420  -0.264 0.792197    
## A2Somewhat likely              0.069245   0.019727   3.510 0.000462 ***
## A2Somewhat unlikely            0.007311   0.022146   0.330 0.741352    
## IV1                            0.104500   0.020113   5.196 2.34e-07 ***
## IV2                            0.040246   0.024176   1.665 0.096198 .  
## IV4                           -0.033214   0.007405  -4.485 7.87e-06 ***
## IV5                            0.003265   0.007669   0.426 0.670402    
## IV6                           -0.013892   0.006235  -2.228 0.026044 *  
## IV7                           -0.007839   0.007845  -0.999 0.317864    
## IV8                           -2.258517  16.465300  -0.137 0.890917    
## IV9                           -2.242993  16.465197  -0.136 0.891662    
## IV10                          -2.263972  16.465235  -0.138 0.890655    
## IV11                          -2.262722  16.465301  -0.137 0.890716    
## IV12                          -2.260554  16.465244  -0.137 0.890819    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07967,    Adjusted R-squared:  0.06921 
## F-statistic: 7.623 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07967, Adjusted R-squared:  0.06921
summary(modelStep4)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV3 + IV4 + IV5 + IV6 + IV7 + 
##     IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.86322 -0.15288  0.00332  0.17793  0.45312 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   76.323794 402.996274   0.189 0.849814    
## A1No                           0.034181   0.013732   2.489 0.012920 *  
## A2Very likely                  0.057048   0.016796   3.397 0.000701 ***
## A2Neither unlikely or likely  -0.003527   0.020409  -0.173 0.862830    
## A2Somewhat likely              0.069841   0.019742   3.538 0.000417 ***
## A2Somewhat unlikely            0.015585   0.021578   0.722 0.470252    
## IV1                            0.100669   0.020003   5.033 5.46e-07 ***
## IV3                           -1.069649   3.169431  -0.337 0.735798    
## IV4                           -1.103352   3.169872  -0.348 0.727836    
## IV5                           -1.066653   3.169702  -0.337 0.736533    
## IV6                           -1.083914   3.169723  -0.342 0.732433    
## IV7                           -1.078051   3.169516  -0.340 0.733809    
## IV8                           -2.095058  16.480532  -0.127 0.898861    
## IV9                           -2.079762  16.480430  -0.126 0.899595    
## IV10                          -2.100643  16.480468  -0.127 0.898592    
## IV11                          -2.099526  16.480534  -0.127 0.898647    
## IV12                          -2.097243  16.480477  -0.127 0.898756    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2319 on 1409 degrees of freedom
## Multiple R-squared:  0.07793,    Adjusted R-squared:  0.06746 
## F-statistic: 7.443 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07967, Adjusted R-squared:  0.06921 
summary(modelStep3)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + 
##     IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.82707 -0.15586  0.00703  0.17954  0.46098 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  166.382042 406.133332   0.410  0.68211    
## A1No                           0.006553   0.016337   0.401  0.68842    
## A2Very likely                  0.063216   0.016897   3.741  0.00019 ***
## A2Neither unlikely or likely  -0.016499   0.020500  -0.805  0.42104    
## A2Somewhat likely              0.083428   0.019722   4.230 2.48e-05 ***
## A2Somewhat unlikely           -0.011765   0.022073  -0.533  0.59410    
## IV2                            0.026193   0.024253   1.080  0.28033    
## IV3                           -1.221049   3.197073  -0.382  0.70257    
## IV4                           -1.260511   3.197510  -0.394  0.69348    
## IV5                           -1.221014   3.197343  -0.382  0.70261    
## IV6                           -1.239633   3.197361  -0.388  0.69829    
## IV7                           -1.231963   3.197151  -0.385  0.70005    
## IV8                           -5.694777  16.608209  -0.343  0.73173    
## IV9                           -5.673400  16.608150  -0.342  0.73270    
## IV10                          -5.697845  16.608161  -0.343  0.73159    
## IV11                          -5.693986  16.608248  -0.343  0.73177    
## IV12                          -5.691721  16.608192  -0.343  0.73187    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2339 on 1409 degrees of freedom
## Multiple R-squared:  0.06213,    Adjusted R-squared:  0.05148 
## F-statistic: 5.834 on 16 and 1409 DF,  p-value: 1.761e-12
# Multiple R-squared:  0.06213, Adjusted R-squared:  0.05148
summary(modelStep2)
## 
## Call:
## lm(formula = D1 ~ A1 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + 
##     IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.86334 -0.16219  0.00692  0.17751  0.44115 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  64.43224  404.49279   0.159    0.873    
## A1No          0.01772    0.01637   1.083    0.279    
## IV1           0.12667    0.01934   6.550 8.02e-11 ***
## IV2           0.03246    0.02355   1.378    0.168    
## IV3          -1.21847    3.18609  -0.382    0.702    
## IV4          -1.25172    3.18653  -0.393    0.695    
## IV5          -1.21378    3.18638  -0.381    0.703    
## IV6          -1.23210    3.18638  -0.387    0.699    
## IV7          -1.22584    3.18617  -0.385    0.700    
## IV8          -1.44818   16.54810  -0.088    0.930    
## IV9          -1.43622   16.54803  -0.087    0.931    
## IV10         -1.45696   16.54804  -0.088    0.930    
## IV11         -1.45596   16.54813  -0.088    0.930    
## IV12         -1.45165   16.54809  -0.088    0.930    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2333 on 1412 degrees of freedom
## Multiple R-squared:  0.06491,    Adjusted R-squared:  0.0563 
## F-statistic:  7.54 on 13 and 1412 DF,  p-value: 1.449e-14
# Multiple R-squared:  0.06491, Adjusted R-squared:  0.0563 
summary(modelStep1)
## 
## Call:
## lm(formula = D1 ~ A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + 
##     IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.89120 -0.15660  0.00579  0.17867  0.45653 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   71.831847 402.700507   0.178 0.858454    
## A2Very likely                  0.057052   0.016788   3.398 0.000697 ***
## A2Neither unlikely or likely  -0.005173   0.020428  -0.253 0.800143    
## A2Somewhat likely              0.067912   0.019704   3.447 0.000584 ***
## A2Somewhat unlikely            0.004646   0.022081   0.210 0.833388    
## IV1                            0.100941   0.019896   5.073 4.43e-07 ***
## IV2                            0.055939   0.020277   2.759 0.005878 ** 
## IV3                           -1.283137   3.167093  -0.405 0.685431    
## IV4                           -1.316674   3.167526  -0.416 0.677708    
## IV5                           -1.280007   3.167361  -0.404 0.686183    
## IV6                           -1.297498   3.167372  -0.410 0.682129    
## IV7                           -1.291022   3.167171  -0.408 0.683610    
## IV8                           -1.694109  16.465209  -0.103 0.918065    
## IV9                           -1.678922  16.465116  -0.102 0.918796    
## IV10                          -1.699921  16.465154  -0.103 0.917784    
## IV11                          -1.698571  16.465218  -0.103 0.917850    
## IV12                          -1.696545  16.465163  -0.103 0.917947    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2318 on 1409 degrees of freedom
## Multiple R-squared:  0.07885,    Adjusted R-squared:  0.06839 
## F-statistic: 7.538 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07885, Adjusted R-squared:  0.06839
summary(modelStep) 
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88763 -0.15605  0.00551  0.17820  0.45371 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   83.166020 402.760961   0.206 0.836438    
## A1No                           0.019259   0.016373   1.176 0.239674    
## A2Very likely                  0.057044   0.016785   3.398 0.000697 ***
## A2Neither unlikely or likely  -0.005376   0.020426  -0.263 0.792430    
## A2Somewhat likely              0.069225   0.019733   3.508 0.000465 ***
## A2Somewhat unlikely            0.006998   0.022168   0.316 0.752309    
## IV1                            0.104478   0.020120   5.193 2.37e-07 ***
## IV2                            0.040422   0.024188   1.671 0.094918 .  
## IV3                           -1.173692   3.168028  -0.370 0.711080    
## IV4                           -1.207065   3.168465  -0.381 0.703289    
## IV5                           -1.170524   3.168298  -0.369 0.711849    
## IV6                           -1.187689   3.168317  -0.375 0.707818    
## IV7                           -1.181557   3.168107  -0.373 0.709239    
## IV8                           -2.276722  16.470416  -0.138 0.890078    
## IV9                           -2.261145  16.470314  -0.137 0.890824    
## IV10                          -2.282128  16.470352  -0.139 0.889818    
## IV11                          -2.280878  16.470417  -0.138 0.889878    
## IV12                          -2.278793  16.470361  -0.138 0.889978    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2318 on 1408 degrees of freedom
## Multiple R-squared:  0.07976,    Adjusted R-squared:  0.06864 
## F-statistic: 7.178 on 17 and 1408 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07976, Adjusted R-squared:  0.06864
summary(modelStep14)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV9 + IV10 + IV11, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8876 -0.1563  0.0054  0.1782  0.4536 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  28.443161  76.008356   0.374 0.708304    
## A1No                          0.019191   0.016360   1.173 0.240962    
## A2Very likely                 0.057086   0.016777   3.403 0.000686 ***
## A2Neither unlikely or likely -0.005353   0.020418  -0.262 0.793240    
## A2Somewhat likely             0.069196   0.019725   3.508 0.000466 ***
## A2Somewhat unlikely           0.007159   0.022130   0.323 0.746374    
## IV1                           0.104589   0.020096   5.204 2.23e-07 ***
## IV2                           0.040400   0.024179   1.671 0.094976 .  
## IV3                          -1.172382   3.166911  -0.370 0.711291    
## IV4                          -1.205739   3.167348  -0.381 0.703500    
## IV5                          -1.169197   3.167180  -0.369 0.712064    
## IV6                          -1.186370   3.167199  -0.375 0.708029    
## IV7                          -1.180219   3.166989  -0.373 0.709455    
## IV8                           0.002078   0.007464   0.278 0.780701    
## IV9                           0.017640   0.007685   2.295 0.021851 *  
## IV10                         -0.003337   0.008374  -0.399 0.690270    
## IV11                         -0.002078   0.007877  -0.264 0.791976    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07974,    Adjusted R-squared:  0.06929 
## F-statistic: 7.631 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07974, Adjusted R-squared:  0.06929 
summary(modelStep13)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV9 + IV10 + IV12, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8876 -0.1563  0.0054  0.1782  0.4536 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  28.393411  76.013659   0.374 0.708810    
## A1No                          0.019191   0.016360   1.173 0.240963    
## A2Very likely                 0.057086   0.016777   3.403 0.000686 ***
## A2Neither unlikely or likely -0.005353   0.020418  -0.262 0.793242    
## A2Somewhat likely             0.069196   0.019725   3.508 0.000466 ***
## A2Somewhat unlikely           0.007159   0.022130   0.323 0.746367    
## IV1                           0.104589   0.020096   5.204 2.23e-07 ***
## IV2                           0.040400   0.024179   1.671 0.094976 .  
## IV3                          -1.172387   3.166912  -0.370 0.711290    
## IV4                          -1.205743   3.167348  -0.381 0.703499    
## IV5                          -1.169202   3.167180  -0.369 0.712063    
## IV6                          -1.186375   3.167200  -0.375 0.708028    
## IV7                          -1.180224   3.166990  -0.373 0.709454    
## IV8                           0.004156   0.006240   0.666 0.505498    
## IV9                           0.019718   0.005959   3.309 0.000959 ***
## IV10                         -0.001260   0.007071  -0.178 0.858629    
## IV12                          0.002077   0.007877   0.264 0.792027    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07974,    Adjusted R-squared:  0.06929 
## F-statistic: 7.631 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07974, Adjusted R-squared:  0.06929 
summary(modelStep12)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV9 + IV11 + IV12, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8876 -0.1563  0.0054  0.1782  0.4536 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  28.363164  76.013695   0.373 0.709106    
## A1No                          0.019191   0.016360   1.173 0.240964    
## A2Very likely                 0.057086   0.016777   3.403 0.000686 ***
## A2Neither unlikely or likely -0.005353   0.020418  -0.262 0.793243    
## A2Somewhat likely             0.069196   0.019725   3.508 0.000466 ***
## A2Somewhat unlikely           0.007159   0.022130   0.324 0.746360    
## IV1                           0.104589   0.020096   5.204 2.23e-07 ***
## IV2                           0.040400   0.024179   1.671 0.094976 .  
## IV3                          -1.172386   3.166912  -0.370 0.711290    
## IV4                          -1.205743   3.167348  -0.381 0.703499    
## IV5                          -1.169201   3.167180  -0.369 0.712063    
## IV6                          -1.186374   3.167200  -0.375 0.708028    
## IV7                          -1.180223   3.166990  -0.373 0.709455    
## IV8                           0.005416   0.007624   0.710 0.477585    
## IV9                           0.020978   0.007278   2.882 0.004007 ** 
## IV11                          0.001259   0.007071   0.178 0.858676    
## IV12                          0.003337   0.008374   0.399 0.690322    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07974,    Adjusted R-squared:  0.06929 
## F-statistic: 7.631 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07974, Adjusted R-squared:  0.06929 
summary(modelStep11)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8876 -0.1563  0.0054  0.1782  0.4536 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  28.866932  76.013878   0.380 0.704182    
## A1No                          0.019192   0.016360   1.173 0.240949    
## A2Very likely                 0.057086   0.016777   3.403 0.000686 ***
## A2Neither unlikely or likely -0.005353   0.020418  -0.262 0.793235    
## A2Somewhat likely             0.069196   0.019725   3.508 0.000466 ***
## A2Somewhat unlikely           0.007158   0.022130   0.323 0.746414    
## IV1                           0.104588   0.020097   5.204 2.24e-07 ***
## IV2                           0.040400   0.024179   1.671 0.094974 .  
## IV3                          -1.172399   3.166911  -0.370 0.711287    
## IV4                          -1.205755   3.167347  -0.381 0.703496    
## IV5                          -1.169214   3.167180  -0.369 0.712060    
## IV6                          -1.186387   3.167199  -0.375 0.708025    
## IV7                          -1.180236   3.166989  -0.373 0.709452    
## IV8                          -0.015562   0.006825  -2.280 0.022751 *  
## IV10                         -0.020978   0.007278  -2.882 0.004006 ** 
## IV11                         -0.019719   0.005959  -3.309 0.000959 ***
## IV12                         -0.017641   0.007685  -2.296 0.021847 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07974,    Adjusted R-squared:  0.06929 
## F-statistic: 7.631 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07974, Adjusted R-squared:  0.06929
summary(modelStep10)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8876 -0.1563  0.0054  0.1782  0.4536 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  28.493133  76.010441   0.375 0.707822    
## A1No                          0.019191   0.016360   1.173 0.240961    
## A2Very likely                 0.057086   0.016777   3.403 0.000686 ***
## A2Neither unlikely or likely -0.005353   0.020418  -0.262 0.793242    
## A2Somewhat likely             0.069196   0.019725   3.508 0.000466 ***
## A2Somewhat unlikely           0.007159   0.022130   0.323 0.746374    
## IV1                           0.104589   0.020096   5.204 2.23e-07 ***
## IV2                           0.040400   0.024179   1.671 0.094976 .  
## IV3                          -1.172386   3.166911  -0.370 0.711290    
## IV4                          -1.205742   3.167348  -0.381 0.703499    
## IV5                          -1.169201   3.167180  -0.369 0.712063    
## IV6                          -1.186374   3.167199  -0.375 0.708028    
## IV7                          -1.180223   3.166989  -0.373 0.709455    
## IV9                           0.015562   0.006825   2.280 0.022755 *  
## IV10                         -0.005416   0.007623  -0.710 0.477546    
## IV11                         -0.004156   0.006240  -0.666 0.505465    
## IV12                         -0.002079   0.007464  -0.279 0.780653    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07974,    Adjusted R-squared:  0.06929 
## F-statistic: 7.631 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07974, Adjusted R-squared:  0.06929
summary(modelStep9)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88725 -0.15633  0.00521  0.17830  0.45310 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   54.358535 395.164118   0.138 0.890608    
## A1No                           0.019439   0.016361   1.188 0.234982    
## A2Very likely                  0.057129   0.016779   3.405 0.000680 ***
## A2Neither unlikely or likely  -0.005380   0.020420  -0.263 0.792210    
## A2Somewhat likely              0.069245   0.019727   3.510 0.000462 ***
## A2Somewhat unlikely            0.007313   0.022146   0.330 0.741262    
## IV1                            0.104501   0.020113   5.196 2.34e-07 ***
## IV2                            0.040245   0.024176   1.665 0.096201 .  
## IV3                            0.007832   0.007845   0.998 0.318311    
## IV4                           -0.025378   0.008361  -3.035 0.002448 ** 
## IV5                            0.011100   0.008719   1.273 0.203210    
## IV6                           -0.006057   0.008241  -0.735 0.462463    
## IV8                           -2.258005  16.465307  -0.137 0.890942    
## IV9                           -2.242483  16.465205  -0.136 0.891686    
## IV10                          -2.263462  16.465243  -0.137 0.890680    
## IV11                          -2.262212  16.465309  -0.137 0.890740    
## IV12                          -2.260046  16.465252  -0.137 0.890844    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07966,    Adjusted R-squared:  0.06921 
## F-statistic: 7.623 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07966, Adjusted R-squared:  0.06921 
summary(modelStep8)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV7 + 
##     IV8 + IV9 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88725 -0.15634  0.00521  0.17830  0.45309 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   54.217655 395.167806   0.137 0.890891    
## A1No                           0.019440   0.016361   1.188 0.234945    
## A2Very likely                  0.057130   0.016779   3.405 0.000680 ***
## A2Neither unlikely or likely  -0.005380   0.020420  -0.263 0.792226    
## A2Somewhat likely              0.069246   0.019727   3.510 0.000462 ***
## A2Somewhat unlikely            0.007315   0.022146   0.330 0.741203    
## IV1                            0.104502   0.020113   5.196 2.34e-07 ***
## IV2                            0.040244   0.024176   1.665 0.096212 .  
## IV3                            0.013886   0.006235   2.227 0.026093 *  
## IV4                           -0.019323   0.006708  -2.881 0.004027 ** 
## IV5                            0.017154   0.007204   2.381 0.017387 *  
## IV7                            0.006049   0.008241   0.734 0.463056    
## IV8                           -2.258189  16.465318  -0.137 0.890933    
## IV9                           -2.242667  16.465216  -0.136 0.891678    
## IV10                          -2.263646  16.465254  -0.137 0.890671    
## IV11                          -2.262397  16.465319  -0.137 0.890731    
## IV12                          -2.260227  16.465262  -0.137 0.890835    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07966,    Adjusted R-squared:  0.06921 
## F-statistic: 7.623 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07966, Adjusted R-squared:  0.06921 
modelStep11 <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11a <- lm(D1 ~ A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11b <- lm(D1 ~ A1 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11c <- lm(D1 ~ A1 + A2 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11d <- lm(D1 ~ A1 + A2 + IV1 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11e <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11f <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV5 + IV6 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11g <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV6 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11h <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11i <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11j <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV10 + IV11 + IV12, data = noout)
modelStep11k <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV11 + IV12, data = noout)
modelStep11l <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV10 + IV12, data = noout)
modelStep11m <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + IV8 + IV10 + IV11, data = noout)
summary(modelStep11)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8876 -0.1563  0.0054  0.1782  0.4536 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  28.866932  76.013878   0.380 0.704182    
## A1No                          0.019192   0.016360   1.173 0.240949    
## A2Very likely                 0.057086   0.016777   3.403 0.000686 ***
## A2Neither unlikely or likely -0.005353   0.020418  -0.262 0.793235    
## A2Somewhat likely             0.069196   0.019725   3.508 0.000466 ***
## A2Somewhat unlikely           0.007158   0.022130   0.323 0.746414    
## IV1                           0.104588   0.020097   5.204 2.24e-07 ***
## IV2                           0.040400   0.024179   1.671 0.094974 .  
## IV3                          -1.172399   3.166911  -0.370 0.711287    
## IV4                          -1.205755   3.167347  -0.381 0.703496    
## IV5                          -1.169214   3.167180  -0.369 0.712060    
## IV6                          -1.186387   3.167199  -0.375 0.708025    
## IV7                          -1.180236   3.166989  -0.373 0.709452    
## IV8                          -0.015562   0.006825  -2.280 0.022751 *  
## IV10                         -0.020978   0.007278  -2.882 0.004006 ** 
## IV11                         -0.019719   0.005959  -3.309 0.000959 ***
## IV12                         -0.017641   0.007685  -2.296 0.021847 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1409 degrees of freedom
## Multiple R-squared:  0.07974,    Adjusted R-squared:  0.06929 
## F-statistic: 7.631 on 16 and 1409 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07974, Adjusted R-squared:  0.06929
summary(modelStep11a)
## 
## Call:
## lm(formula = D1 ~ A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.89116 -0.15659  0.00576  0.17867  0.45645 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  31.507354  75.990683   0.415 0.678482    
## A2Very likely                 0.057083   0.016779   3.402 0.000688 ***
## A2Neither unlikely or likely -0.005156   0.020420  -0.252 0.800705    
## A2Somewhat likely             0.067894   0.019696   3.447 0.000583 ***
## A2Somewhat unlikely           0.004771   0.022039   0.216 0.828652    
## IV1                           0.101032   0.019869   5.085 4.17e-07 ***
## IV2                           0.055882   0.020262   2.758 0.005892 ** 
## IV3                          -1.281890   3.165958  -0.405 0.685614    
## IV4                          -1.315415   3.166390  -0.415 0.677890    
## IV5                          -1.278747   3.166226  -0.404 0.686369    
## IV6                          -1.296245   3.166237  -0.409 0.682311    
## IV7                          -1.289754   3.166035  -0.407 0.683797    
## IV8                          -0.015178   0.006818  -2.226 0.026168 *  
## IV10                         -0.020996   0.007279  -2.884 0.003980 ** 
## IV11                         -0.019639   0.005959  -3.296 0.001006 ** 
## IV12                         -0.017618   0.007686  -2.292 0.022036 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1410 degrees of freedom
## Multiple R-squared:  0.07884,    Adjusted R-squared:  0.06904 
## F-statistic: 8.046 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07884, Adjusted R-squared:  0.06904
summary(modelStep11b)
## 
## Call:
## lm(formula = D1 ~ A1 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.86334 -0.16223  0.00689  0.17746  0.44116 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)    
## (Intercept) 29.959075  76.447235   0.392  0.69520    
## A1No         0.017669   0.016350   1.081  0.28002    
## IV1          0.126720   0.019323   6.558 7.64e-11 ***
## IV2          0.032477   0.023545   1.379  0.16800    
## IV3         -1.218318   3.184975  -0.383  0.70213    
## IV4         -1.251563   3.185414  -0.393  0.69445    
## IV5         -1.213614   3.185257  -0.381  0.70325    
## IV6         -1.231950   3.185260  -0.387  0.69899    
## IV7         -1.225674   3.185047  -0.385  0.70043    
## IV8         -0.011961   0.006812  -1.756  0.07933 .  
## IV10        -0.020739   0.007313  -2.836  0.00463 ** 
## IV11        -0.019737   0.005988  -3.296  0.00101 ** 
## IV12        -0.015424   0.007711  -2.000  0.04566 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2332 on 1413 degrees of freedom
## Multiple R-squared:  0.0649, Adjusted R-squared:  0.05696 
## F-statistic: 8.173 on 12 and 1413 DF,  p-value: 4.924e-15
# Multiple R-squared:  0.0649,  Adjusted R-squared:  0.05696 
summary(modelStep11c)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.82680 -0.15607  0.00721  0.17956  0.46077 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  30.144530  76.713378   0.393 0.694416    
## A1No                          0.006349   0.016321   0.389 0.697325    
## A2Very likely                 0.063337   0.016888   3.750 0.000184 ***
## A2Neither unlikely or likely -0.016470   0.020493  -0.804 0.421714    
## A2Somewhat likely             0.083392   0.019715   4.230 2.49e-05 ***
## A2Somewhat unlikely          -0.011413   0.022042  -0.518 0.604690    
## IV2                           0.026100   0.024244   1.077 0.281857    
## IV3                          -1.217923   3.196058  -0.381 0.703209    
## IV4                          -1.257362   3.196495  -0.393 0.694116    
## IV5                          -1.217855   3.196328  -0.381 0.703248    
## IV6                          -1.236499   3.196346  -0.387 0.698927    
## IV7                          -1.228776   3.196136  -0.384 0.700698    
## IV8                          -0.021358   0.006796  -3.143 0.001708 ** 
## IV10                         -0.024442   0.007314  -3.342 0.000854 ***
## IV11                         -0.020553   0.006011  -3.419 0.000646 ***
## IV12                         -0.018307   0.007755  -2.361 0.018368 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2338 on 1410 degrees of freedom
## Multiple R-squared:  0.06205,    Adjusted R-squared:  0.05208 
## F-statistic: 6.219 on 15 and 1410 DF,  p-value: 7.211e-13
# Multiple R-squared:  0.06205, Adjusted R-squared:  0.05208 
summary(modelStep11d)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV3 + IV4 + IV5 + IV6 + IV7 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.86320 -0.15286  0.00335  0.17797  0.45303 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  26.381675  76.047596   0.347 0.728711    
## A1No                          0.034112   0.013716   2.487 0.013000 *  
## A2Very likely                 0.057086   0.016787   3.401 0.000691 ***
## A2Neither unlikely or likely -0.003506   0.020401  -0.172 0.863571    
## A2Somewhat likely             0.069814   0.019734   3.538 0.000417 ***
## A2Somewhat unlikely           0.015728   0.021541   0.730 0.465422    
## IV1                           0.100773   0.019979   5.044 5.15e-07 ***
## IV3                          -1.068511   3.168312  -0.337 0.735979    
## IV4                          -1.102199   3.168752  -0.348 0.728017    
## IV5                          -1.065499   3.168583  -0.336 0.736717    
## IV6                          -1.082768   3.168603  -0.342 0.732614    
## IV7                          -1.076887   3.168396  -0.340 0.733995    
## IV8                          -0.015284   0.006828  -2.238 0.025345 *  
## IV10                         -0.020876   0.007282  -2.867 0.004209 ** 
## IV11                         -0.019750   0.005962  -3.313 0.000948 ***
## IV12                         -0.017476   0.007689  -2.273 0.023189 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2319 on 1410 degrees of freedom
## Multiple R-squared:  0.07792,    Adjusted R-squared:  0.06811 
## F-statistic: 7.943 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07792, Adjusted R-squared:  0.06811
summary(modelStep11e)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV7 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88721 -0.15644  0.00511  0.17826  0.45301 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.726463   0.160492   4.526 6.50e-06 ***
## A1No                          0.019370   0.016348   1.185 0.236256    
## A2Very likely                 0.057170   0.016770   3.409 0.000670 ***
## A2Neither unlikely or likely -0.005358   0.020412  -0.262 0.792995    
## A2Somewhat likely             0.069216   0.019719   3.510 0.000462 ***
## A2Somewhat unlikely           0.007469   0.022107   0.338 0.735517    
## IV1                           0.104609   0.020090   5.207 2.20e-07 ***
## IV2                           0.040224   0.024167   1.664 0.096253 .  
## IV4                          -0.033198   0.007401  -4.485 7.87e-06 ***
## IV5                           0.003281   0.007666   0.428 0.668712    
## IV6                          -0.013884   0.006233  -2.228 0.026069 *  
## IV7                          -0.007812   0.007840  -0.996 0.319227    
## IV8                          -0.015510   0.006822  -2.274 0.023137 *  
## IV10                         -0.020975   0.007276  -2.883 0.004001 ** 
## IV11                         -0.019715   0.005957  -3.310 0.000957 ***
## IV12                         -0.017555   0.007679  -2.286 0.022395 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1410 degrees of freedom
## Multiple R-squared:  0.07965,    Adjusted R-squared:  0.06986 
## F-statistic: 8.135 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07965, Adjusted R-squared:  0.06986 
summary(modelStep11f)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV5 + IV6 + IV7 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8872 -0.1564  0.0051  0.1783  0.4530 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  -0.070240   0.076465  -0.919 0.358465    
## A1No                          0.019376   0.016348   1.185 0.236129    
## A2Very likely                 0.057172   0.016770   3.409 0.000670 ***
## A2Neither unlikely or likely -0.005358   0.020412  -0.262 0.792995    
## A2Somewhat likely             0.069217   0.019719   3.510 0.000462 ***
## A2Somewhat unlikely           0.007478   0.022107   0.338 0.735220    
## IV1                           0.104612   0.020090   5.207 2.20e-07 ***
## IV2                           0.040220   0.024167   1.664 0.096290 .  
## IV3                           0.033187   0.007400   4.485 7.90e-06 ***
## IV5                           0.036474   0.007704   4.734 2.42e-06 ***
## IV6                           0.019309   0.006705   2.880 0.004038 ** 
## IV7                           0.025379   0.008357   3.037 0.002435 ** 
## IV8                          -0.015505   0.006822  -2.273 0.023180 *  
## IV10                         -0.020972   0.007276  -2.883 0.004005 ** 
## IV11                         -0.019713   0.005957  -3.309 0.000959 ***
## IV12                         -0.017551   0.007679  -2.286 0.022427 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1410 degrees of freedom
## Multiple R-squared:  0.07965,    Adjusted R-squared:  0.06986 
## F-statistic: 8.135 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07965, Adjusted R-squared:  0.06986
summary(modelStep11g)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV6 + IV7 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88722 -0.15645  0.00511  0.17827  0.45302 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.805305   0.178334   4.516 6.84e-06 ***
## A1No                          0.019370   0.016348   1.185 0.236267    
## A2Very likely                 0.057169   0.016770   3.409 0.000670 ***
## A2Neither unlikely or likely -0.005357   0.020412  -0.262 0.793001    
## A2Somewhat likely             0.069216   0.019719   3.510 0.000462 ***
## A2Somewhat unlikely           0.007468   0.022107   0.338 0.735570    
## IV1                           0.104610   0.020090   5.207 2.20e-07 ***
## IV2                           0.040225   0.024167   1.664 0.096246 .  
## IV3                          -0.003288   0.007665  -0.429 0.668060    
## IV4                          -0.036483   0.007705  -4.735 2.41e-06 ***
## IV6                          -0.017169   0.007201  -2.384 0.017249 *  
## IV7                          -0.011097   0.008715  -1.273 0.203121    
## IV8                          -0.015510   0.006822  -2.274 0.023143 *  
## IV10                         -0.020977   0.007276  -2.883 0.003996 ** 
## IV11                         -0.019715   0.005957  -3.310 0.000957 ***
## IV12                         -0.017555   0.007679  -2.286 0.022394 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1410 degrees of freedom
## Multiple R-squared:  0.07965,    Adjusted R-squared:  0.06986 
## F-statistic: 8.136 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07965, Adjusted R-squared:  0.06986
summary(modelStep11h)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV7 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8872 -0.1564  0.0051  0.1783  0.4530 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.393294   0.150759   2.609 0.009183 ** 
## A1No                          0.019373   0.016348   1.185 0.236190    
## A2Very likely                 0.057171   0.016770   3.409 0.000670 ***
## A2Neither unlikely or likely -0.005357   0.020412  -0.262 0.793024    
## A2Somewhat likely             0.069217   0.019719   3.510 0.000462 ***
## A2Somewhat unlikely           0.007474   0.022107   0.338 0.735369    
## IV1                           0.104611   0.020090   5.207  2.2e-07 ***
## IV2                           0.040222   0.024167   1.664 0.096267 .  
## IV3                           0.013878   0.006232   2.227 0.026118 *  
## IV4                          -0.019315   0.006705  -2.881 0.004028 ** 
## IV5                           0.017163   0.007201   2.383 0.017289 *  
## IV7                           0.006068   0.008236   0.737 0.461387    
## IV8                          -0.015509   0.006822  -2.273 0.023151 *  
## IV10                         -0.020975   0.007276  -2.883 0.004001 ** 
## IV11                         -0.019717   0.005957  -3.310 0.000957 ***
## IV12                         -0.017554   0.007679  -2.286 0.022406 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1410 degrees of freedom
## Multiple R-squared:  0.07965,    Adjusted R-squared:  0.06986 
## F-statistic: 8.135 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07965, Adjusted R-squared:  0.06986 
summary(modelStep11i)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88721 -0.15645  0.00511  0.17826  0.45302 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.539065   0.178796   3.015 0.002616 ** 
## A1No                          0.019371   0.016348   1.185 0.236227    
## A2Very likely                 0.057170   0.016770   3.409 0.000670 ***
## A2Neither unlikely or likely -0.005357   0.020412  -0.262 0.793008    
## A2Somewhat likely             0.069216   0.019719   3.510 0.000462 ***
## A2Somewhat unlikely           0.007472   0.022107   0.338 0.735428    
## IV1                           0.104610   0.020090   5.207  2.2e-07 ***
## IV2                           0.040224   0.024167   1.664 0.096256 .  
## IV3                           0.007804   0.007840   0.995 0.319674    
## IV4                          -0.025390   0.008358  -3.038 0.002427 ** 
## IV5                           0.011089   0.008716   1.272 0.203484    
## IV6                          -0.006077   0.008237  -0.738 0.460796    
## IV8                          -0.015509   0.006822  -2.273 0.023150 *  
## IV10                         -0.020974   0.007276  -2.883 0.004001 ** 
## IV11                         -0.019715   0.005957  -3.310 0.000958 ***
## IV12                         -0.017557   0.007679  -2.286 0.022381 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1410 degrees of freedom
## Multiple R-squared:  0.07965,    Adjusted R-squared:  0.06986 
## F-statistic: 8.135 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07965, Adjusted R-squared:  0.06986 
summary(modelStep11j)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.89855 -0.15454  0.00808  0.17718  0.42667 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  25.038055  76.108395   0.329 0.742221    
## A1No                          0.017401   0.016365   1.063 0.287819    
## A2Very likely                 0.055586   0.016789   3.311 0.000954 ***
## A2Neither unlikely or likely -0.004107   0.020441  -0.201 0.840808    
## A2Somewhat likely             0.065116   0.019673   3.310 0.000957 ***
## A2Somewhat unlikely           0.009415   0.022141   0.425 0.670733    
## IV1                           0.112064   0.019857   5.644 2.01e-08 ***
## IV2                           0.039052   0.024208   1.613 0.106927    
## IV3                          -1.023803   3.170951  -0.323 0.746842    
## IV4                          -1.046508   3.171289  -0.330 0.741453    
## IV5                          -1.017898   3.171196  -0.321 0.748271    
## IV6                          -1.034786   3.171212  -0.326 0.744241    
## IV7                          -1.027876   3.170995  -0.324 0.745873    
## IV10                         -0.014057   0.006625  -2.122 0.034014 *  
## IV11                         -0.012511   0.005058  -2.473 0.013505 *  
## IV12                         -0.009301   0.006769  -1.374 0.169617    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.232 on 1410 degrees of freedom
## Multiple R-squared:  0.07635,    Adjusted R-squared:  0.06652 
## F-statistic:  7.77 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07635, Adjusted R-squared:  0.06652 
summary(modelStep11k)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.87824 -0.15761  0.00958  0.18069  0.42754 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  28.373709  76.210431   0.372 0.709720    
## A1No                          0.019288   0.016402   1.176 0.239803    
## A2Very likely                 0.057766   0.016819   3.435 0.000611 ***
## A2Neither unlikely or likely -0.005681   0.020471  -0.277 0.781440    
## A2Somewhat likely             0.068403   0.019774   3.459 0.000558 ***
## A2Somewhat unlikely           0.010133   0.022163   0.457 0.647598    
## IV1                           0.109886   0.020064   5.477 5.12e-08 ***
## IV2                           0.039816   0.024241   1.643 0.100704    
## IV3                          -1.160248   3.175105  -0.365 0.714853    
## IV4                          -1.186701   3.175538  -0.374 0.708683    
## IV5                          -1.166323   3.175377  -0.367 0.713449    
## IV6                          -1.174216   3.175394  -0.370 0.711598    
## IV7                          -1.167624   3.175183  -0.368 0.713126    
## IV8                          -0.007357   0.006219  -1.183 0.237042    
## IV11                         -0.012101   0.005354  -2.260 0.023970 *  
## IV12                         -0.009342   0.007144  -1.308 0.191156    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2323 on 1410 degrees of freedom
## Multiple R-squared:  0.07432,    Adjusted R-squared:  0.06447 
## F-statistic: 7.547 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07432, Adjusted R-squared:  0.06447 
summary(modelStep11l)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV10 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88757 -0.15571  0.00796  0.17971  0.44284 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  28.229324  76.281401   0.370 0.711387    
## A1No                          0.018574   0.016416   1.131 0.258066    
## A2Very likely                 0.057580   0.016835   3.420 0.000644 ***
## A2Neither unlikely or likely -0.007231   0.020482  -0.353 0.724126    
## A2Somewhat likely             0.066752   0.019780   3.375 0.000759 ***
## A2Somewhat unlikely           0.005757   0.022204   0.259 0.795466    
## IV1                           0.106378   0.020160   5.277 1.52e-07 ***
## IV2                           0.040656   0.024264   1.676 0.094052 .  
## IV3                          -1.157239   3.178064  -0.364 0.715813    
## IV4                          -1.180538   3.178495  -0.371 0.710385    
## IV5                          -1.153063   3.178333  -0.363 0.716817    
## IV6                          -1.176743   3.178355  -0.370 0.711262    
## IV7                          -1.162919   3.178141  -0.366 0.714486    
## IV8                          -0.003580   0.005806  -0.617 0.537638    
## IV10                         -0.010296   0.006546  -1.573 0.115966    
## IV12                         -0.008612   0.007209  -1.194 0.232491    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2325 on 1410 degrees of freedom
## Multiple R-squared:  0.07259,    Adjusted R-squared:  0.06272 
## F-statistic: 7.358 on 15 and 1410 DF,  p-value: 6.782e-16
# Multiple R-squared:  0.07259, Adjusted R-squared:  0.06272 
summary(modelStep11m)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV10 + IV11, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88173 -0.15359  0.00545  0.17498  0.42740 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  23.426758  76.091872   0.308 0.758223    
## A1No                          0.019096   0.016384   1.166 0.244007    
## A2Very likely                 0.054476   0.016764   3.250 0.001183 ** 
## A2Neither unlikely or likely -0.006901   0.020438  -0.338 0.735686    
## A2Somewhat likely             0.066360   0.019716   3.366 0.000784 ***
## A2Somewhat unlikely           0.004552   0.022134   0.206 0.837106    
## IV1                           0.105357   0.020124   5.235  1.9e-07 ***
## IV2                           0.039685   0.024214   1.639 0.101451    
## IV3                          -0.952601   3.170252  -0.300 0.763854    
## IV4                          -0.980964   3.170623  -0.309 0.757069    
## IV5                          -0.949256   3.170520  -0.299 0.764678    
## IV6                          -0.965593   3.170528  -0.305 0.760752    
## IV7                          -0.968142   3.170430  -0.305 0.760132    
## IV8                          -0.008105   0.006012  -1.348 0.177817    
## IV10                         -0.014719   0.006758  -2.178 0.029572 *  
## IV11                         -0.014862   0.005579  -2.664 0.007809 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2321 on 1410 degrees of freedom
## Multiple R-squared:  0.0763, Adjusted R-squared:  0.06647 
## F-statistic: 7.765 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.0763,  Adjusted R-squared:  0.06647 
modelStep11i <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ia <- lm(D1 ~ A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ib <- lm(D1 ~ A1 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ic <- lm(D1 ~ A1 + A2 + IV2 + IV3 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11id <- lm(D1 ~ A1 + A2 + IV1 + IV3 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ie <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11if <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ig <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ih <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4  + IV5 + IV7 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ii <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4  + IV5 + IV6 + IV7  + IV10 + IV11 + IV12, data = noout)
modelStep11ij <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7  + IV8 + IV11 + IV12, data = noout)
modelStep11ik <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7  + IV8  + IV10 + IV12, data = noout)
modelStep11il <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV7  + IV8  + IV10 + IV11, data = noout)
summary(modelStep11i)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88721 -0.15645  0.00511  0.17826  0.45302 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.539065   0.178796   3.015 0.002616 ** 
## A1No                          0.019371   0.016348   1.185 0.236227    
## A2Very likely                 0.057170   0.016770   3.409 0.000670 ***
## A2Neither unlikely or likely -0.005357   0.020412  -0.262 0.793008    
## A2Somewhat likely             0.069216   0.019719   3.510 0.000462 ***
## A2Somewhat unlikely           0.007472   0.022107   0.338 0.735428    
## IV1                           0.104610   0.020090   5.207  2.2e-07 ***
## IV2                           0.040224   0.024167   1.664 0.096256 .  
## IV3                           0.007804   0.007840   0.995 0.319674    
## IV4                          -0.025390   0.008358  -3.038 0.002427 ** 
## IV5                           0.011089   0.008716   1.272 0.203484    
## IV6                          -0.006077   0.008237  -0.738 0.460796    
## IV8                          -0.015509   0.006822  -2.273 0.023150 *  
## IV10                         -0.020974   0.007276  -2.883 0.004001 ** 
## IV11                         -0.019715   0.005957  -3.310 0.000958 ***
## IV12                         -0.017557   0.007679  -2.286 0.022381 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1410 degrees of freedom
## Multiple R-squared:  0.07965,    Adjusted R-squared:  0.06986 
## F-statistic: 8.135 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07965, Adjusted R-squared:  0.06986
summary(modelStep11ia)
## 
## Call:
## lm(formula = D1 ~ A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV8 + 
##     IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.89078 -0.15656  0.00571  0.17881  0.45582 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.550956   0.178540   3.086 0.002069 ** 
## A2Very likely                 0.057176   0.016772   3.409 0.000671 ***
## A2Neither unlikely or likely -0.005159   0.020414  -0.253 0.800543    
## A2Somewhat likely             0.067902   0.019690   3.449 0.000580 ***
## A2Somewhat unlikely           0.005090   0.022019   0.231 0.817218    
## IV1                           0.101020   0.019863   5.086 4.15e-07 ***
## IV2                           0.055848   0.020256   2.757 0.005907 ** 
## IV3                           0.007829   0.007841   0.998 0.318224    
## IV4                          -0.025521   0.008359  -3.053 0.002306 ** 
## IV5                           0.011080   0.008717   1.271 0.203917    
## IV6                          -0.006413   0.008233  -0.779 0.436191    
## IV8                          -0.015115   0.006815  -2.218 0.026708 *  
## IV10                         -0.020992   0.007277  -2.885 0.003976 ** 
## IV11                         -0.019634   0.005957  -3.296 0.001006 ** 
## IV12                         -0.017526   0.007680  -2.282 0.022637 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1411 degrees of freedom
## Multiple R-squared:  0.07874,    Adjusted R-squared:  0.0696 
## F-statistic: 8.614 on 14 and 1411 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07874, Adjusted R-squared:  0.0696 
summary(modelStep11ib)
## 
## Call:
## lm(formula = D1 ~ A1 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + IV8 + 
##     IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8630 -0.1622  0.0071  0.1775  0.4407 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  0.540625   0.179854   3.006  0.00269 ** 
## A1No         0.017832   0.016339   1.091  0.27530    
## IV1          0.126697   0.019318   6.559 7.59e-11 ***
## IV2          0.032380   0.023537   1.376  0.16912    
## IV3          0.007325   0.007888   0.929  0.35322    
## IV4         -0.025752   0.008407  -3.063  0.00223 ** 
## IV5          0.012136   0.008759   1.386  0.16608    
## IV6         -0.006198   0.008289  -0.748  0.45476    
## IV8         -0.011910   0.006809  -1.749  0.08046 .  
## IV10        -0.020742   0.007311  -2.837  0.00462 ** 
## IV11        -0.019733   0.005987  -3.296  0.00100 ** 
## IV12        -0.015333   0.007705  -1.990  0.04679 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2332 on 1414 degrees of freedom
## Multiple R-squared:  0.06481,    Adjusted R-squared:  0.05753 
## F-statistic: 8.908 on 11 and 1414 DF,  p-value: 1.705e-15
# Multiple R-squared:  0.06481, Adjusted R-squared:  0.05753
summary(modelStep11ic)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV2 + IV3 + IV4 + IV5 + IV6 + IV8 + 
##     IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.82639 -0.15631  0.00702  0.17980  0.46014 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.651637   0.179119   3.638 0.000285 ***
## A1No                          0.006534   0.016309   0.401 0.688777    
## A2Very likely                 0.063427   0.016881   3.757 0.000179 ***
## A2Neither unlikely or likely -0.016477   0.020487  -0.804 0.421376    
## A2Somewhat likely             0.083416   0.019709   4.232 2.46e-05 ***
## A2Somewhat unlikely          -0.011090   0.022019  -0.504 0.614588    
## IV2                           0.025914   0.024232   1.069 0.285064    
## IV3                           0.010820   0.007891   1.371 0.170516    
## IV4                          -0.028452   0.008414  -3.381 0.000741 ***
## IV5                           0.010990   0.008796   1.249 0.211694    
## IV6                          -0.007646   0.008307  -0.920 0.357497    
## IV8                          -0.021303   0.006792  -3.136 0.001746 ** 
## IV10                         -0.024439   0.007312  -3.342 0.000853 ***
## IV11                         -0.020550   0.006009  -3.420 0.000645 ***
## IV12                         -0.018221   0.007749  -2.351 0.018841 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2338 on 1411 degrees of freedom
## Multiple R-squared:  0.06196,    Adjusted R-squared:  0.05265 
## F-statistic: 6.657 on 14 and 1411 DF,  p-value: 2.891e-13
# Multiple R-squared:  0.06196, Adjusted R-squared:  0.05265 
summary(modelStep11id)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV3 + IV4 + IV5 + IV6 + IV8 + 
##     IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.86294 -0.15301  0.00321  0.17786  0.45248 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.534390   0.178886   2.987 0.002863 ** 
## A1No                          0.034217   0.013709   2.496 0.012674 *  
## A2Very likely                 0.057164   0.016781   3.407 0.000676 ***
## A2Neither unlikely or likely -0.003518   0.020395  -0.172 0.863092    
## A2Somewhat likely             0.069830   0.019728   3.540 0.000414 ***
## A2Somewhat unlikely           0.015981   0.021522   0.743 0.457876    
## IV1                           0.100808   0.019972   5.047 5.06e-07 ***
## IV3                           0.008344   0.007838   1.065 0.287269    
## IV4                          -0.025195   0.008363  -3.013 0.002635 ** 
## IV5                           0.011447   0.008718   1.313 0.189399    
## IV6                          -0.005815   0.008241  -0.706 0.480552    
## IV8                          -0.015236   0.006824  -2.233 0.025728 *  
## IV10                         -0.020873   0.007280  -2.867 0.004203 ** 
## IV11                         -0.019747   0.005960  -3.313 0.000946 ***
## IV12                         -0.017400   0.007683  -2.265 0.023688 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2318 on 1411 degrees of freedom
## Multiple R-squared:  0.07784,    Adjusted R-squared:  0.06869 
## F-statistic: 8.508 on 14 and 1411 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07784, Adjusted R-squared:  0.06869 
summary(modelStep11ie)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + 
##     IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88149 -0.15667  0.00614  0.17812  0.46227 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.649155   0.140491   4.621 4.18e-06 ***
## A1No                          0.019414   0.016347   1.188 0.235187    
## A2Very likely                 0.057236   0.016770   3.413 0.000661 ***
## A2Neither unlikely or likely -0.004947   0.020408  -0.242 0.808516    
## A2Somewhat likely             0.069227   0.019719   3.511 0.000461 ***
## A2Somewhat unlikely           0.008026   0.022100   0.363 0.716520    
## IV1                           0.106088   0.020035   5.295 1.38e-07 ***
## IV2                           0.041218   0.024147   1.707 0.088039 .  
## IV4                          -0.030250   0.006784  -4.459 8.89e-06 ***
## IV5                           0.006094   0.007127   0.855 0.392624    
## IV6                          -0.011820   0.005879  -2.011 0.044547 *  
## IV8                          -0.014081   0.006669  -2.111 0.034923 *  
## IV10                         -0.020827   0.007274  -2.863 0.004257 ** 
## IV11                         -0.019222   0.005936  -3.238 0.001231 ** 
## IV12                         -0.020833   0.006939  -3.002 0.002726 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1411 degrees of freedom
## Multiple R-squared:  0.07901,    Adjusted R-squared:  0.06987 
## F-statistic: 8.646 on 14 and 1411 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07901, Adjusted R-squared:  0.06987
summary(modelStep11if)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV5 + IV6 + IV8 + 
##     IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88558 -0.15266  0.00393  0.17515  0.43769 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.036600   0.068088   0.538 0.590976    
## A1No                          0.020029   0.016394   1.222 0.222017    
## A2Very likely                 0.057607   0.016818   3.425 0.000632 ***
## A2Neither unlikely or likely -0.006148   0.020470  -0.300 0.763964    
## A2Somewhat likely             0.068312   0.019774   3.455 0.000567 ***
## A2Somewhat unlikely           0.005635   0.022163   0.254 0.799339    
## IV1                           0.108904   0.020099   5.418 7.06e-08 ***
## IV2                           0.039193   0.024235   1.617 0.106064    
## IV3                           0.021716   0.006382   3.403 0.000686 ***
## IV5                           0.026801   0.007035   3.809 0.000145 ***
## IV6                           0.010778   0.006106   1.765 0.077726 .  
## IV8                          -0.008038   0.006382  -1.260 0.208028    
## IV10                         -0.015067   0.007031  -2.143 0.032300 *  
## IV11                         -0.014549   0.005725  -2.541 0.011157 *  
## IV12                         -0.002146   0.005782  -0.371 0.710523    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2323 on 1411 degrees of freedom
## Multiple R-squared:  0.07363,    Adjusted R-squared:  0.06444 
## F-statistic: 8.011 on 14 and 1411 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07363, Adjusted R-squared:  0.06444 
summary(modelStep11ig)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88721 -0.15645  0.00511  0.17826  0.45302 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.539065   0.178796   3.015 0.002616 ** 
## A1No                          0.019371   0.016348   1.185 0.236227    
## A2Very likely                 0.057170   0.016770   3.409 0.000670 ***
## A2Neither unlikely or likely -0.005357   0.020412  -0.262 0.793008    
## A2Somewhat likely             0.069216   0.019719   3.510 0.000462 ***
## A2Somewhat unlikely           0.007472   0.022107   0.338 0.735428    
## IV1                           0.104610   0.020090   5.207  2.2e-07 ***
## IV2                           0.040224   0.024167   1.664 0.096256 .  
## IV3                           0.007804   0.007840   0.995 0.319674    
## IV4                          -0.025390   0.008358  -3.038 0.002427 ** 
## IV5                           0.011089   0.008716   1.272 0.203484    
## IV6                          -0.006077   0.008237  -0.738 0.460796    
## IV8                          -0.015509   0.006822  -2.273 0.023150 *  
## IV10                         -0.020974   0.007276  -2.883 0.004001 ** 
## IV11                         -0.019715   0.005957  -3.310 0.000958 ***
## IV12                         -0.017557   0.007679  -2.286 0.022381 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1410 degrees of freedom
## Multiple R-squared:  0.07965,    Adjusted R-squared:  0.06986 
## F-statistic: 8.135 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07965, Adjusted R-squared:  0.06986 
summary(modelStep11ih)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV7 + 
##     IV8 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8872 -0.1564  0.0051  0.1783  0.4530 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.393294   0.150759   2.609 0.009183 ** 
## A1No                          0.019373   0.016348   1.185 0.236190    
## A2Very likely                 0.057171   0.016770   3.409 0.000670 ***
## A2Neither unlikely or likely -0.005357   0.020412  -0.262 0.793024    
## A2Somewhat likely             0.069217   0.019719   3.510 0.000462 ***
## A2Somewhat unlikely           0.007474   0.022107   0.338 0.735369    
## IV1                           0.104611   0.020090   5.207  2.2e-07 ***
## IV2                           0.040222   0.024167   1.664 0.096267 .  
## IV3                           0.013878   0.006232   2.227 0.026118 *  
## IV4                          -0.019315   0.006705  -2.881 0.004028 ** 
## IV5                           0.017163   0.007201   2.383 0.017289 *  
## IV7                           0.006068   0.008236   0.737 0.461387    
## IV8                          -0.015509   0.006822  -2.273 0.023151 *  
## IV10                         -0.020975   0.007276  -2.883 0.004001 ** 
## IV11                         -0.019717   0.005957  -3.310 0.000957 ***
## IV12                         -0.017554   0.007679  -2.286 0.022406 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1410 degrees of freedom
## Multiple R-squared:  0.07965,    Adjusted R-squared:  0.06986 
## F-statistic: 8.135 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07965, Adjusted R-squared:  0.06986 
summary(modelStep11ii)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.89855 -0.15454  0.00808  0.17718  0.42667 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  25.038055  76.108395   0.329 0.742221    
## A1No                          0.017401   0.016365   1.063 0.287819    
## A2Very likely                 0.055586   0.016789   3.311 0.000954 ***
## A2Neither unlikely or likely -0.004107   0.020441  -0.201 0.840808    
## A2Somewhat likely             0.065116   0.019673   3.310 0.000957 ***
## A2Somewhat unlikely           0.009415   0.022141   0.425 0.670733    
## IV1                           0.112064   0.019857   5.644 2.01e-08 ***
## IV2                           0.039052   0.024208   1.613 0.106927    
## IV3                          -1.023803   3.170951  -0.323 0.746842    
## IV4                          -1.046508   3.171289  -0.330 0.741453    
## IV5                          -1.017898   3.171196  -0.321 0.748271    
## IV6                          -1.034786   3.171212  -0.326 0.744241    
## IV7                          -1.027876   3.170995  -0.324 0.745873    
## IV10                         -0.014057   0.006625  -2.122 0.034014 *  
## IV11                         -0.012511   0.005058  -2.473 0.013505 *  
## IV12                         -0.009301   0.006769  -1.374 0.169617    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.232 on 1410 degrees of freedom
## Multiple R-squared:  0.07635,    Adjusted R-squared:  0.06652 
## F-statistic:  7.77 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07635, Adjusted R-squared:  0.06652
summary(modelStep11ij)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.87824 -0.15761  0.00958  0.18069  0.42754 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  28.373709  76.210431   0.372 0.709720    
## A1No                          0.019288   0.016402   1.176 0.239803    
## A2Very likely                 0.057766   0.016819   3.435 0.000611 ***
## A2Neither unlikely or likely -0.005681   0.020471  -0.277 0.781440    
## A2Somewhat likely             0.068403   0.019774   3.459 0.000558 ***
## A2Somewhat unlikely           0.010133   0.022163   0.457 0.647598    
## IV1                           0.109886   0.020064   5.477 5.12e-08 ***
## IV2                           0.039816   0.024241   1.643 0.100704    
## IV3                          -1.160248   3.175105  -0.365 0.714853    
## IV4                          -1.186701   3.175538  -0.374 0.708683    
## IV5                          -1.166323   3.175377  -0.367 0.713449    
## IV6                          -1.174216   3.175394  -0.370 0.711598    
## IV7                          -1.167624   3.175183  -0.368 0.713126    
## IV8                          -0.007357   0.006219  -1.183 0.237042    
## IV11                         -0.012101   0.005354  -2.260 0.023970 *  
## IV12                         -0.009342   0.007144  -1.308 0.191156    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2323 on 1410 degrees of freedom
## Multiple R-squared:  0.07432,    Adjusted R-squared:  0.06447 
## F-statistic: 7.547 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07432, Adjusted R-squared:  0.06447
summary(modelStep11ik)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV10 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88757 -0.15571  0.00796  0.17971  0.44284 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  28.229324  76.281401   0.370 0.711387    
## A1No                          0.018574   0.016416   1.131 0.258066    
## A2Very likely                 0.057580   0.016835   3.420 0.000644 ***
## A2Neither unlikely or likely -0.007231   0.020482  -0.353 0.724126    
## A2Somewhat likely             0.066752   0.019780   3.375 0.000759 ***
## A2Somewhat unlikely           0.005757   0.022204   0.259 0.795466    
## IV1                           0.106378   0.020160   5.277 1.52e-07 ***
## IV2                           0.040656   0.024264   1.676 0.094052 .  
## IV3                          -1.157239   3.178064  -0.364 0.715813    
## IV4                          -1.180538   3.178495  -0.371 0.710385    
## IV5                          -1.153063   3.178333  -0.363 0.716817    
## IV6                          -1.176743   3.178355  -0.370 0.711262    
## IV7                          -1.162919   3.178141  -0.366 0.714486    
## IV8                          -0.003580   0.005806  -0.617 0.537638    
## IV10                         -0.010296   0.006546  -1.573 0.115966    
## IV12                         -0.008612   0.007209  -1.194 0.232491    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2325 on 1410 degrees of freedom
## Multiple R-squared:  0.07259,    Adjusted R-squared:  0.06272 
## F-statistic: 7.358 on 15 and 1410 DF,  p-value: 6.782e-16
# Multiple R-squared:  0.07259, Adjusted R-squared:  0.06272
summary(modelStep11il)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV3 + IV4 + IV5 + IV6 + 
##     IV7 + IV8 + IV10 + IV11, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88173 -0.15359  0.00545  0.17498  0.42740 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  23.426758  76.091872   0.308 0.758223    
## A1No                          0.019096   0.016384   1.166 0.244007    
## A2Very likely                 0.054476   0.016764   3.250 0.001183 ** 
## A2Neither unlikely or likely -0.006901   0.020438  -0.338 0.735686    
## A2Somewhat likely             0.066360   0.019716   3.366 0.000784 ***
## A2Somewhat unlikely           0.004552   0.022134   0.206 0.837106    
## IV1                           0.105357   0.020124   5.235  1.9e-07 ***
## IV2                           0.039685   0.024214   1.639 0.101451    
## IV3                          -0.952601   3.170252  -0.300 0.763854    
## IV4                          -0.980964   3.170623  -0.309 0.757069    
## IV5                          -0.949256   3.170520  -0.299 0.764678    
## IV6                          -0.965593   3.170528  -0.305 0.760752    
## IV7                          -0.968142   3.170430  -0.305 0.760132    
## IV8                          -0.008105   0.006012  -1.348 0.177817    
## IV10                         -0.014719   0.006758  -2.178 0.029572 *  
## IV11                         -0.014862   0.005579  -2.664 0.007809 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2321 on 1410 degrees of freedom
## Multiple R-squared:  0.0763, Adjusted R-squared:  0.06647 
## F-statistic: 7.765 on 15 and 1410 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.0763,  Adjusted R-squared:  0.06647
modelStep11ie <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11iea <- lm(D1 ~ A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ieb <- lm(D1 ~ A1 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ieac <- lm(D1 ~ A1 + A2 + IV2 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ied <- lm(D1 ~ A1 + A2 + IV1 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11iee <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV5 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ief <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ieg <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ieh <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV10 + IV11 + IV12, data = noout)
modelStep11iei <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + IV11 + IV12, data = noout)
modelStep11iej <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + IV10 + IV12, data = noout)
modelStep11iek <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + IV10 + IV11, data = noout)
summary(modelStep11ie)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + 
##     IV10 + IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88149 -0.15667  0.00614  0.17812  0.46227 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.649155   0.140491   4.621 4.18e-06 ***
## A1No                          0.019414   0.016347   1.188 0.235187    
## A2Very likely                 0.057236   0.016770   3.413 0.000661 ***
## A2Neither unlikely or likely -0.004947   0.020408  -0.242 0.808516    
## A2Somewhat likely             0.069227   0.019719   3.511 0.000461 ***
## A2Somewhat unlikely           0.008026   0.022100   0.363 0.716520    
## IV1                           0.106088   0.020035   5.295 1.38e-07 ***
## IV2                           0.041218   0.024147   1.707 0.088039 .  
## IV4                          -0.030250   0.006784  -4.459 8.89e-06 ***
## IV5                           0.006094   0.007127   0.855 0.392624    
## IV6                          -0.011820   0.005879  -2.011 0.044547 *  
## IV8                          -0.014081   0.006669  -2.111 0.034923 *  
## IV10                         -0.020827   0.007274  -2.863 0.004257 ** 
## IV11                         -0.019222   0.005936  -3.238 0.001231 ** 
## IV12                         -0.020833   0.006939  -3.002 0.002726 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1411 degrees of freedom
## Multiple R-squared:  0.07901,    Adjusted R-squared:  0.06987 
## F-statistic: 8.646 on 14 and 1411 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07901, Adjusted R-squared:  0.06987 
summary(modelStep11iea)
## 
## Call:
## lm(formula = D1 ~ A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + IV10 + 
##     IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88505 -0.15898  0.00758  0.17847  0.46511 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.661419   0.140132   4.720 2.59e-06 ***
## A2Very likely                 0.057242   0.016772   3.413 0.000661 ***
## A2Neither unlikely or likely -0.004746   0.020410  -0.233 0.816155    
## A2Somewhat likely             0.067910   0.019690   3.449 0.000579 ***
## A2Somewhat unlikely           0.005641   0.022012   0.256 0.797775    
## IV1                           0.102494   0.019808   5.174 2.62e-07 ***
## IV2                           0.056881   0.020230   2.812 0.004995 ** 
## IV4                          -0.030397   0.006784  -4.481 8.04e-06 ***
## IV5                           0.006069   0.007128   0.852 0.394619    
## IV6                          -0.012175   0.005872  -2.073 0.038315 *  
## IV8                          -0.013682   0.006662  -2.054 0.040177 *  
## IV10                         -0.020844   0.007275  -2.865 0.004231 ** 
## IV11                         -0.019140   0.005937  -3.224 0.001293 ** 
## IV12                         -0.020812   0.006940  -2.999 0.002757 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2317 on 1412 degrees of freedom
## Multiple R-squared:  0.07809,    Adjusted R-squared:  0.0696 
## F-statistic:   9.2 on 13 and 1412 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07809, Adjusted R-squared:  0.0696 
summary(modelStep11ieb)
## 
## Call:
## lm(formula = D1 ~ A1 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + IV10 + 
##     IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.85771 -0.16266  0.00751  0.18064  0.44973 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  0.644157   0.141127   4.564 5.44e-06 ***
## A1No         0.017848   0.016339   1.092  0.27485    
## IV1          0.127936   0.019270   6.639 4.49e-11 ***
## IV2          0.033464   0.023507   1.424  0.15479    
## IV4         -0.030311   0.006824  -4.442 9.62e-06 ***
## IV5          0.007452   0.007160   1.041  0.29817    
## IV6         -0.011597   0.005909  -1.963  0.04988 *  
## IV8         -0.010586   0.006657  -1.590  0.11202    
## IV10        -0.020611   0.007309  -2.820  0.00487 ** 
## IV11        -0.019267   0.005965  -3.230  0.00127 ** 
## IV12        -0.018405   0.006959  -2.645  0.00826 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2332 on 1415 degrees of freedom
## Multiple R-squared:  0.06424,    Adjusted R-squared:  0.05762 
## F-statistic: 9.713 on 10 and 1415 DF,  p-value: 7.809e-16
# Multiple R-squared:  0.06424, Adjusted R-squared:  0.05762
summary(modelStep11ieac)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV2 + IV4 + IV5 + IV6 + IV8 + IV10 + 
##     IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.81722 -0.15598  0.01046  0.17917  0.47319 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.807316   0.138587   5.825 7.05e-09 ***
## A1No                          0.006341   0.016314   0.389 0.697581    
## A2Very likely                 0.063642   0.016886   3.769 0.000171 ***
## A2Neither unlikely or likely -0.016123   0.020492  -0.787 0.431515    
## A2Somewhat likely             0.083710   0.019714   4.246 2.32e-05 ***
## A2Somewhat unlikely          -0.010682   0.022024  -0.485 0.627736    
## IV2                           0.027019   0.024226   1.115 0.264920    
## IV4                          -0.035287   0.006781  -5.204 2.24e-07 ***
## IV5                           0.004026   0.007184   0.560 0.575246    
## IV6                          -0.015684   0.005889  -2.663 0.007826 ** 
## IV8                          -0.019426   0.006655  -2.919 0.003567 ** 
## IV10                         -0.024302   0.007314  -3.323 0.000914 ***
## IV11                         -0.019879   0.005991  -3.318 0.000930 ***
## IV12                         -0.022799   0.006995  -3.259 0.001143 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2338 on 1412 degrees of freedom
## Multiple R-squared:  0.06071,    Adjusted R-squared:  0.05206 
## F-statistic:  7.02 on 13 and 1412 DF,  p-value: 2.401e-13
# Multiple R-squared:  0.06071, Adjusted R-squared:  0.05206
summary(modelStep11ied)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV4 + IV5 + IV6 + IV8 + IV10 + 
##     IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.85618 -0.15596  0.00355  0.17914  0.46239 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.652168   0.140575   4.639 3.82e-06 ***
## A1No                          0.034656   0.013703   2.529 0.011546 *  
## A2Very likely                 0.057234   0.016781   3.411 0.000666 ***
## A2Neither unlikely or likely -0.003029   0.020391  -0.149 0.881933    
## A2Somewhat likely             0.069857   0.019728   3.541 0.000412 ***
## A2Somewhat unlikely           0.016800   0.021509   0.781 0.434883    
## IV1                           0.102289   0.019925   5.134 3.24e-07 ***
## IV4                          -0.030394   0.006788  -4.478 8.16e-06 ***
## IV5                           0.006108   0.007132   0.856 0.391886    
## IV6                          -0.011959   0.005882  -2.033 0.042232 *  
## IV8                          -0.013699   0.006670  -2.054 0.040175 *  
## IV10                         -0.020713   0.007279  -2.846 0.004496 ** 
## IV11                         -0.019220   0.005940  -3.236 0.001242 ** 
## IV12                         -0.020903   0.006943  -3.011 0.002654 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2318 on 1412 degrees of freedom
## Multiple R-squared:  0.0771, Adjusted R-squared:  0.06861 
## F-statistic: 9.074 on 13 and 1412 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.0771,  Adjusted R-squared:  0.06861
summary(modelStep11iee)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV5 + IV6 + IV8 + IV10 + 
##     IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.86011 -0.15957  0.00987  0.17902  0.45144 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.0953570  0.0661079   1.442 0.149399    
## A1No                          0.0207411  0.0164537   1.261 0.207669    
## A2Very likely                 0.0582394  0.0168801   3.450 0.000577 ***
## A2Neither unlikely or likely -0.0050524  0.0205437  -0.246 0.805769    
## A2Somewhat likely             0.0676255  0.0198467   3.407 0.000674 ***
## A2Somewhat unlikely           0.0064926  0.0222448   0.292 0.770427    
## IV1                           0.1186146  0.0199696   5.940 3.59e-09 ***
## IV2                           0.0425597  0.0243055   1.751 0.080158 .  
## IV5                           0.0184090  0.0066136   2.783 0.005449 ** 
## IV6                           0.0001469  0.0052652   0.028 0.977753    
## IV8                           0.0040330  0.0053244   0.757 0.448905    
## IV10                         -0.0096687  0.0068757  -1.406 0.159881    
## IV11                         -0.0082922  0.0054424  -1.524 0.127829    
## IV12                         -0.0035198  0.0057891  -0.608 0.543282    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2332 on 1412 degrees of freedom
## Multiple R-squared:  0.06603,    Adjusted R-squared:  0.05743 
## F-statistic: 7.679 on 13 and 1412 DF,  p-value: 6.821e-15
# Multiple R-squared:  0.06603, Adjusted R-squared:  0.05743
summary(modelStep11ief)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6 + IV8 + IV10 + 
##     IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.87760 -0.15578  0.00675  0.17776  0.46141 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.692370   0.131075   5.282 1.48e-07 ***
## A1No                          0.019373   0.016346   1.185 0.236129    
## A2Very likely                 0.057750   0.016758   3.446 0.000585 ***
## A2Neither unlikely or likely -0.004952   0.020406  -0.243 0.808304    
## A2Somewhat likely             0.069865   0.019703   3.546 0.000404 ***
## A2Somewhat unlikely           0.008898   0.022075   0.403 0.686945    
## IV1                           0.105149   0.020003   5.257 1.69e-07 ***
## IV2                           0.041242   0.024144   1.708 0.087831 .  
## IV4                          -0.032498   0.006253  -5.197 2.32e-07 ***
## IV6                          -0.013864   0.005371  -2.581 0.009941 ** 
## IV8                          -0.014566   0.006644  -2.192 0.028520 *  
## IV10                         -0.017973   0.006462  -2.781 0.005490 ** 
## IV11                         -0.019268   0.005935  -3.246 0.001196 ** 
## IV12                         -0.022004   0.006802  -3.235 0.001244 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1412 degrees of freedom
## Multiple R-squared:  0.07853,    Adjusted R-squared:  0.07004 
## F-statistic: 9.256 on 13 and 1412 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07853, Adjusted R-squared:  0.07004
summary(modelStep11ieg)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV8 + IV10 + 
##     IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88486 -0.15921  0.00493  0.17613  0.45373 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.523076   0.125857   4.156 3.43e-05 ***
## A1No                          0.021084   0.016344   1.290 0.197248    
## A2Very likely                 0.057967   0.016784   3.454 0.000569 ***
## A2Neither unlikely or likely -0.002828   0.020402  -0.139 0.889788    
## A2Somewhat likely             0.069832   0.019738   3.538 0.000416 ***
## A2Somewhat unlikely           0.009476   0.022112   0.429 0.668324    
## IV1                           0.111088   0.019902   5.582 2.85e-08 ***
## IV2                           0.041888   0.024170   1.733 0.083304 .  
## IV4                          -0.024023   0.006042  -3.976 7.37e-05 ***
## IV5                           0.011919   0.006518   1.828 0.067689 .  
## IV8                          -0.012036   0.006598  -1.824 0.068354 .  
## IV10                         -0.020916   0.007282  -2.872 0.004136 ** 
## IV11                         -0.022969   0.005642  -4.071 4.94e-05 ***
## IV12                         -0.017385   0.006731  -2.583 0.009897 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2319 on 1412 degrees of freedom
## Multiple R-squared:  0.07637,    Adjusted R-squared:  0.06786 
## F-statistic:  8.98 on 13 and 1412 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07637, Adjusted R-squared:  0.06786 
summary(modelStep11ieh)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV10 + 
##     IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.89452 -0.15509  0.00823  0.17804  0.43260 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.436063   0.097849   4.457 8.99e-06 ***
## A1No                          0.017677   0.016347   1.081 0.279707    
## A2Very likely                 0.055776   0.016776   3.325 0.000908 ***
## A2Neither unlikely or likely -0.003953   0.020427  -0.194 0.846580    
## A2Somewhat likely             0.065356   0.019657   3.325 0.000908 ***
## A2Somewhat unlikely           0.009873   0.022110   0.447 0.655279    
## IV1                           0.112491   0.019829   5.673 1.70e-08 ***
## IV2                           0.039510   0.024162   1.635 0.102236    
## IV4                          -0.021526   0.005387  -3.996 6.78e-05 ***
## IV5                           0.007376   0.007110   1.037 0.299686    
## IV6                          -0.009928   0.005817  -1.707 0.088109 .  
## IV10                         -0.014340   0.006601  -2.172 0.030003 *  
## IV11                         -0.012621   0.005052  -2.498 0.012597 *  
## IV12                         -0.011450   0.005335  -2.146 0.032040 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2319 on 1412 degrees of freedom
## Multiple R-squared:  0.0761, Adjusted R-squared:  0.06759 
## F-statistic: 8.946 on 13 and 1412 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.0761,  Adjusted R-squared:  0.06759
summary(modelStep11iei)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + 
##     IV11 + IV12, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8725 -0.1588  0.0094  0.1806  0.4310 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.453478   0.123060   3.685 0.000237 ***
## A1No                          0.019506   0.016389   1.190 0.234176    
## A2Very likely                 0.057907   0.016811   3.445 0.000589 ***
## A2Neither unlikely or likely -0.005296   0.020459  -0.259 0.795785    
## A2Somewhat likely             0.068438   0.019767   3.462 0.000552 ***
## A2Somewhat unlikely           0.010946   0.022133   0.495 0.620993    
## IV1                           0.111262   0.020004   5.562 3.19e-08 ***
## IV2                           0.040583   0.024207   1.676 0.093864 .  
## IV4                          -0.023568   0.006386  -3.690 0.000232 ***
## IV5                          -0.003269   0.006348  -0.515 0.606661    
## IV6                          -0.011923   0.005894  -2.023 0.043264 *  
## IV8                          -0.006015   0.006060  -0.993 0.321113    
## IV11                         -0.011685   0.005334  -2.191 0.028638 *  
## IV12                         -0.012399   0.006299  -1.969 0.049193 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2322 on 1412 degrees of freedom
## Multiple R-squared:  0.07365,    Adjusted R-squared:  0.06513 
## F-statistic: 8.636 on 13 and 1412 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07365, Adjusted R-squared:  0.06513
summary(modelStep11iej)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + 
##     IV10 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88302 -0.15650  0.00883  0.17886  0.44183 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.401402   0.118225   3.395 0.000705 ***
## A1No                          0.018794   0.016401   1.146 0.252042    
## A2Very likely                 0.057703   0.016826   3.430 0.000622 ***
## A2Neither unlikely or likely -0.006901   0.020467  -0.337 0.736033    
## A2Somewhat likely             0.066825   0.019771   3.380 0.000745 ***
## A2Somewhat unlikely           0.006496   0.022169   0.293 0.769536    
## IV1                           0.107444   0.020098   5.346 1.05e-07 ***
## IV2                           0.041202   0.024227   1.701 0.089230 .  
## IV4                          -0.021179   0.006199  -3.416 0.000653 ***
## IV5                           0.006304   0.007150   0.882 0.378140    
## IV6                          -0.017796   0.005600  -3.178 0.001517 ** 
## IV8                          -0.002706   0.005688  -0.476 0.634310    
## IV10                         -0.010381   0.006542  -1.587 0.112743    
## IV12                         -0.011082   0.006272  -1.767 0.077471 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2324 on 1412 degrees of freedom
## Multiple R-squared:  0.07216,    Adjusted R-squared:  0.06362 
## F-statistic: 8.447 on 13 and 1412 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07216, Adjusted R-squared:  0.06362
summary(modelStep11iek)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV5 + IV6 + IV8 + 
##     IV10 + IV11, data = noout)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8649 -0.1597  0.0095  0.1789  0.4317 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.300605   0.079347   3.789 0.000158 ***
## A1No                          0.019291   0.016394   1.177 0.239506    
## A2Very likely                 0.053531   0.016772   3.192 0.001445 ** 
## A2Neither unlikely or likely -0.006599   0.020458  -0.323 0.747086    
## A2Somewhat likely             0.065130   0.019727   3.302 0.000985 ***
## A2Somewhat unlikely           0.004965   0.022139   0.224 0.822575    
## IV1                           0.109307   0.020063   5.448    6e-08 ***
## IV2                           0.041651   0.024214   1.720 0.085633 .  
## IV4                          -0.018853   0.005638  -3.344 0.000849 ***
## IV5                           0.010319   0.007006   1.473 0.141036    
## IV6                          -0.007459   0.005713  -1.306 0.191859    
## IV8                          -0.001256   0.005136  -0.245 0.806798    
## IV10                         -0.011556   0.006605  -1.750 0.080393 .  
## IV11                         -0.011488   0.005363  -2.142 0.032362 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2323 on 1412 degrees of freedom
## Multiple R-squared:  0.07312,    Adjusted R-squared:  0.06459 
## F-statistic: 8.569 on 13 and 1412 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07312, Adjusted R-squared:  0.06459 
modelStep11iefa <- lm(D1 ~ A2 + IV1 + IV2 + IV4 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11iefb <- lm(D1 ~ A1 + IV1 + IV2 + IV4 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11iefc <- lm(D1 ~ A1 + A2 + IV2 + IV4 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11iefd <- lm(D1 ~ A1 + A2 + IV1 + IV4 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11iefe <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11ieff <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV8 + IV10 + IV11 + IV12, data = noout)
modelStep11iefg <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6+ IV10 + IV11 + IV12, data = noout)
modelStep11iefh <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6+ IV8 + IV11 + IV12, data = noout)
modelStep11iefi <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6+ IV8 + IV10 + IV12, data = noout)
modelStep11iefj <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6+ IV8 + IV10+ IV11, data = noout)
summary(modelStep11iefa)
## 
## Call:
## lm(formula = D1 ~ A2 + IV1 + IV2 + IV4 + IV6 + IV8 + IV10 + IV11 + 
##     IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88117 -0.15935  0.00693  0.17661  0.46425 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.704432   0.130698   5.390 8.26e-08 ***
## A2Very likely                 0.057754   0.016760   3.446 0.000586 ***
## A2Neither unlikely or likely -0.004752   0.020408  -0.233 0.815926    
## A2Somewhat likely             0.068548   0.019674   3.484 0.000509 ***
## A2Somewhat unlikely           0.006514   0.021986   0.296 0.767056    
## IV1                           0.101566   0.019776   5.136 3.20e-07 ***
## IV2                           0.056871   0.020228   2.812 0.004999 ** 
## IV4                          -0.032635   0.006253  -5.219 2.07e-07 ***
## IV6                          -0.014209   0.005364  -2.649 0.008157 ** 
## IV8                          -0.014167   0.006637  -2.135 0.032966 *  
## IV10                         -0.018001   0.006463  -2.785 0.005423 ** 
## IV11                         -0.019186   0.005936  -3.232 0.001257 ** 
## IV12                         -0.021979   0.006802  -3.231 0.001262 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1413 degrees of freedom
## Multiple R-squared:  0.07761,    Adjusted R-squared:  0.06978 
## F-statistic: 9.908 on 12 and 1413 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07761, Adjusted R-squared:  0.06978
summary(modelStep11iefb)
## 
## Call:
## lm(formula = D1 ~ A1 + IV1 + IV2 + IV4 + IV6 + IV8 + IV10 + IV11 + 
##     IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.85277 -0.16385  0.00839  0.18022  0.44924 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  0.697297   0.131570   5.300 1.34e-07 ***
## A1No         0.017701   0.016338   1.083  0.27881    
## IV1          0.126827   0.019242   6.591 6.13e-11 ***
## IV2          0.033706   0.023506   1.434  0.15182    
## IV4         -0.033064   0.006291  -5.256 1.70e-07 ***
## IV6         -0.014107   0.005394  -2.615  0.00901 ** 
## IV8         -0.011165   0.006634  -1.683  0.09260 .  
## IV10        -0.017124   0.006496  -2.636  0.00848 ** 
## IV11        -0.019319   0.005965  -3.239  0.00123 ** 
## IV12        -0.019810   0.006827  -2.902  0.00377 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2332 on 1416 degrees of freedom
## Multiple R-squared:  0.06352,    Adjusted R-squared:  0.05757 
## F-statistic: 10.67 on 9 and 1416 DF,  p-value: 3.781e-16
# Multiple R-squared:  0.06352, Adjusted R-squared:  0.05757
summary(modelStep11iefc)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV2 + IV4 + IV6 + IV8 + IV10 + IV11 + 
##     IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.81502 -0.15678  0.01106  0.17903  0.47255 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.835025   0.129438   6.451 1.52e-10 ***
## A1No                          0.006390   0.016310   0.392 0.695263    
## A2Very likely                 0.063945   0.016873   3.790 0.000157 ***
## A2Neither unlikely or likely -0.016061   0.020486  -0.784 0.433173    
## A2Somewhat likely             0.084048   0.019700   4.266 2.12e-05 ***
## A2Somewhat unlikely          -0.009995   0.021984  -0.455 0.649443    
## IV2                           0.027117   0.024219   1.120 0.263052    
## IV4                          -0.036747   0.006259  -5.871 5.39e-09 ***
## IV6                          -0.017015   0.005387  -3.158 0.001620 ** 
## IV8                          -0.019717   0.006633  -2.972 0.003004 ** 
## IV10                         -0.022390   0.006468  -3.462 0.000553 ***
## IV11                         -0.019906   0.005990  -3.323 0.000912 ***
## IV12                         -0.023564   0.006859  -3.436 0.000608 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2338 on 1413 degrees of freedom
## Multiple R-squared:  0.0605, Adjusted R-squared:  0.05252 
## F-statistic: 7.582 on 12 and 1413 DF,  p-value: 9.689e-14
# Multiple R-squared:  0.0605,  Adjusted R-squared:  0.05252 
summary(modelStep11iefd)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV4 + IV6 + IV8 + IV10 + IV11 + 
##     IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.85227 -0.15558  0.00366  0.17884  0.46152 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.695481   0.131152   5.303 1.32e-07 ***
## A1No                          0.034623   0.013702   2.527  0.01162 *  
## A2Very likely                 0.057749   0.016769   3.444  0.00059 ***
## A2Neither unlikely or likely -0.003033   0.020389  -0.149  0.88176    
## A2Somewhat likely             0.070497   0.019712   3.576  0.00036 ***
## A2Somewhat unlikely           0.017679   0.021482   0.823  0.41068    
## IV1                           0.101346   0.019893   5.095 3.97e-07 ***
## IV4                          -0.032647   0.006257  -5.218 2.08e-07 ***
## IV6                          -0.014007   0.005374  -2.607  0.00924 ** 
## IV8                          -0.014186   0.006645  -2.135  0.03295 *  
## IV10                         -0.017852   0.006466  -2.761  0.00584 ** 
## IV11                         -0.019266   0.005939  -3.244  0.00121 ** 
## IV12                         -0.022077   0.006806  -3.244  0.00121 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2318 on 1413 degrees of freedom
## Multiple R-squared:  0.07662,    Adjusted R-squared:  0.06878 
## F-statistic: 9.771 on 12 and 1413 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07662, Adjusted R-squared:  0.06878 
summary(modelStep11iefe)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV6 + IV8 + IV10 + IV11 + 
##     IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.84065 -0.15959  0.01216  0.17839  0.44567 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.102668   0.066213   1.551 0.121228    
## A1No                          0.020946   0.016493   1.270 0.204289    
## A2Very likely                 0.060331   0.016904   3.569 0.000370 ***
## A2Neither unlikely or likely -0.005099   0.020593  -0.248 0.804485    
## A2Somewhat likely             0.069471   0.019883   3.494 0.000491 ***
## A2Somewhat unlikely           0.009185   0.022277   0.412 0.680167    
## IV1                           0.118587   0.020017   5.924 3.94e-09 ***
## IV2                           0.042996   0.024363   1.765 0.077810 .  
## IV6                          -0.003955   0.005067  -0.781 0.435201    
## IV8                           0.007091   0.005222   1.358 0.174724    
## IV10                          0.003425   0.005027   0.681 0.495769    
## IV11                         -0.005569   0.005367  -1.038 0.299607    
## IV12                         -0.003110   0.005801  -0.536 0.591935    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2337 on 1413 degrees of freedom
## Multiple R-squared:  0.0609, Adjusted R-squared:  0.05293 
## F-statistic: 7.636 on 12 and 1413 DF,  p-value: 7.372e-14
# Multiple R-squared:  0.0609,  Adjusted R-squared:  0.05293 
summary(modelStep11ieff)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV8 + IV10 + IV11 + 
##     IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.87713 -0.15869  0.00767  0.17656  0.45378 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.573257   0.122930   4.663 3.41e-06 ***
## A1No                          0.021665   0.016354   1.325 0.185485    
## A2Very likely                 0.059467   0.016778   3.544 0.000406 ***
## A2Neither unlikely or likely -0.001982   0.020414  -0.097 0.922683    
## A2Somewhat likely             0.071572   0.019731   3.627 0.000296 ***
## A2Somewhat unlikely           0.012105   0.022084   0.548 0.583691    
## IV1                           0.110913   0.019918   5.568 3.07e-08 ***
## IV2                           0.042214   0.024190   1.745 0.081180 .  
## IV4                          -0.026767   0.005858  -4.570 5.31e-06 ***
## IV8                          -0.012346   0.006602  -1.870 0.061675 .  
## IV10                         -0.014265   0.006313  -2.259 0.024011 *  
## IV11                         -0.024594   0.005576  -4.410 1.11e-05 ***
## IV12                         -0.018733   0.006696  -2.798 0.005216 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2321 on 1413 degrees of freedom
## Multiple R-squared:  0.07418,    Adjusted R-squared:  0.06632 
## F-statistic: 9.435 on 12 and 1413 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07418, Adjusted R-squared:  0.06632 
summary(modelStep11iefg)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6 + IV10 + IV11 + 
##     IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.89033 -0.15590  0.00845  0.17675  0.43030 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.479785   0.088311   5.433 6.52e-08 ***
## A1No                          0.017554   0.016347   1.074 0.283066    
## A2Very likely                 0.056341   0.016768   3.360 0.000800 ***
## A2Neither unlikely or likely -0.003918   0.020428  -0.192 0.847946    
## A2Somewhat likely             0.065971   0.019649   3.358 0.000807 ***
## A2Somewhat unlikely           0.011013   0.022083   0.499 0.618064    
## IV1                           0.111616   0.019811   5.634 2.12e-08 ***
## IV2                           0.039466   0.024163   1.633 0.102624    
## IV4                          -0.023899   0.004877  -4.900 1.07e-06 ***
## IV6                          -0.012339   0.005333  -2.314 0.020816 *  
## IV10                         -0.010587   0.005522  -1.917 0.055422 .  
## IV11                         -0.012400   0.005048  -2.456 0.014151 *  
## IV12                         -0.012483   0.005242  -2.382 0.017371 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2319 on 1413 degrees of freedom
## Multiple R-squared:  0.07539,    Adjusted R-squared:  0.06754 
## F-statistic: 9.601 on 12 and 1413 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07539, Adjusted R-squared:  0.06754
summary(modelStep11iefh)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6 + IV8 + IV11 + 
##     IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.87434 -0.16021  0.00884  0.17897  0.43319 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.405891   0.081246   4.996 6.59e-07 ***
## A1No                          0.019542   0.016385   1.193 0.233179    
## A2Very likely                 0.057620   0.016797   3.430 0.000620 ***
## A2Neither unlikely or likely -0.005325   0.020454  -0.260 0.794637    
## A2Somewhat likely             0.067931   0.019737   3.442 0.000595 ***
## A2Somewhat unlikely           0.010626   0.022118   0.480 0.631021    
## IV1                           0.112382   0.019881   5.653 1.91e-08 ***
## IV2                           0.040508   0.024200   1.674 0.094380 .  
## IV4                          -0.021418   0.004831  -4.433 1.00e-05 ***
## IV6                          -0.010544   0.005249  -2.009 0.044751 *  
## IV8                          -0.004934   0.005684  -0.868 0.385494    
## IV11                         -0.010952   0.005139  -2.131 0.033255 *  
## IV12                         -0.010818   0.005498  -1.968 0.049299 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2322 on 1413 degrees of freedom
## Multiple R-squared:  0.07348,    Adjusted R-squared:  0.06561 
## F-statistic: 9.339 on 12 and 1413 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07348, Adjusted R-squared:  0.06561
summary(modelStep11iefi)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6 + IV8 + IV10 + 
##     IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.87901 -0.15549  0.00891  0.17896  0.43773 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.445491   0.107119   4.159 3.39e-05 ***
## A1No                          0.018750   0.016400   1.143 0.253111    
## A2Very likely                 0.058236   0.016813   3.464 0.000549 ***
## A2Neither unlikely or likely -0.006911   0.020466  -0.338 0.735639    
## A2Somewhat likely             0.067479   0.019755   3.416 0.000654 ***
## A2Somewhat unlikely           0.007394   0.022144   0.334 0.738496    
## IV1                           0.106476   0.020067   5.306 1.30e-07 ***
## IV2                           0.041226   0.024226   1.702 0.089019 .  
## IV4                          -0.023482   0.005622  -4.177 3.13e-05 ***
## IV6                          -0.019924   0.005053  -3.943 8.43e-05 ***
## IV8                          -0.003181   0.005662  -0.562 0.574392    
## IV10                         -0.007403   0.005601  -1.322 0.186497    
## IV12                         -0.012270   0.006125  -2.003 0.045360 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2324 on 1413 degrees of freedom
## Multiple R-squared:  0.07165,    Adjusted R-squared:  0.06377 
## F-statistic: 9.088 on 12 and 1413 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.07165, Adjusted R-squared:  0.06377 
summary(modelStep11iefj)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6 + IV8 + IV10 + 
##     IV11, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.85644 -0.15995  0.01215  0.17693  0.43119 
## 
## Coefficients:
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.3422107  0.0741781   4.613 4.32e-06 ***
## A1No                          0.0192064  0.0164004   1.171 0.241760    
## A2Very likely                 0.0540692  0.0167748   3.223 0.001296 ** 
## A2Neither unlikely or likely -0.0067714  0.0204662  -0.331 0.740801    
## A2Somewhat likely             0.0658488  0.0197292   3.338 0.000867 ***
## A2Somewhat unlikely           0.0061974  0.0221326   0.280 0.779507    
## IV1                           0.1079720  0.0200511   5.385 8.48e-08 ***
## IV2                           0.0417352  0.0242244   1.723 0.085134 .  
## IV4                          -0.0216844  0.0053027  -4.089 4.57e-05 ***
## IV6                          -0.0106270  0.0052943  -2.007 0.044914 *  
## IV8                          -0.0008418  0.0051307  -0.164 0.869699    
## IV10                         -0.0056091  0.0052288  -1.073 0.283580    
## IV11                         -0.0108032  0.0053452  -2.021 0.043459 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2324 on 1413 degrees of freedom
## Multiple R-squared:  0.0717, Adjusted R-squared:  0.06381 
## F-statistic: 9.095 on 12 and 1413 DF,  p-value: < 2.2e-16
# Multiple R-squared:  0.0717,  Adjusted R-squared:  0.06381

## No Adjusted R-squared value is greater than in this step thus we stop the regression.

Prediction using Stepwise Regression

## Highest Adjusted R square model:

modelStep11ief <- lm(D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6 + IV8 + IV10 + IV11 + IV12, data = noout)
summary(modelStep11ief)
## 
## Call:
## lm(formula = D1 ~ A1 + A2 + IV1 + IV2 + IV4 + IV6 + IV8 + IV10 + 
##     IV11 + IV12, data = noout)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.87760 -0.15578  0.00675  0.17776  0.46141 
## 
## Coefficients:
##                               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                   0.692370   0.131075   5.282 1.48e-07 ***
## A1No                          0.019373   0.016346   1.185 0.236129    
## A2Very likely                 0.057750   0.016758   3.446 0.000585 ***
## A2Neither unlikely or likely -0.004952   0.020406  -0.243 0.808304    
## A2Somewhat likely             0.069865   0.019703   3.546 0.000404 ***
## A2Somewhat unlikely           0.008898   0.022075   0.403 0.686945    
## IV1                           0.105149   0.020003   5.257 1.69e-07 ***
## IV2                           0.041242   0.024144   1.708 0.087831 .  
## IV4                          -0.032498   0.006253  -5.197 2.32e-07 ***
## IV6                          -0.013864   0.005371  -2.581 0.009941 ** 
## IV8                          -0.014566   0.006644  -2.192 0.028520 *  
## IV10                         -0.017973   0.006462  -2.781 0.005490 ** 
## IV11                         -0.019268   0.005935  -3.246 0.001196 ** 
## IV12                         -0.022004   0.006802  -3.235 0.001244 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2316 on 1412 degrees of freedom
## Multiple R-squared:  0.07853,    Adjusted R-squared:  0.07004 
## F-statistic: 9.256 on 13 and 1412 DF,  p-value: < 2.2e-16
### Our final model results show that A2 - Very likely, A2 - Somewhat likely, IV1, IV4, IV6, IV8, IV10, IV11 and IV12 are all significant as their p-values are all less than 0.05. We can conclude that these variables are good predictors of our dependent variable D1 which has to do with productivity. Our overall model also has a p-value less than 0.05 with an F-value of 9.306 - With these results, it is safe to say that productivity levels have been affected by the covid19 pandemic and therefore we reject our null hypothesis. This study provides some clarity that Remote work HAS affected the software industry during covid 19 pandemic. 

Prediction using Stepwise Regression - using the the estimate points above

Coefficients: Estimate
(Intercept) 0.69237
A1No 0.019373
A2Very likely 0.05775
A2Neither unlikely or likely 0.004952
A2Somewhat likely 0.069865
A2Somewhat unlikely 0.008898
IV1 0.105149 IV2 0.041242
IV4 -0.032498 IV6 -0.013864
IV8 -0.014566
IV10 -0.017973
IV11 -0.019268
IV12 -0.022004

Random column from dataset

IV1 A1 IV2 A2 IV3 IV4 IV5 IV6 IV7 IV8 IV9 IV10 IV11 IV12 D1

1 Yes 0 Somewhat unlikely 2 6 4 5 7 7 5 5 7 0.5

Calculation results:

0.105149 0.019373 0 0.3465 -0.194988 -0.06932 0 -0.089865 -0.09634 -0.154028

                                                                                                                   -0.133519
                                                                                                                    0.558851
                                                                                                                    

Above are the values from multiplying the selected column with the coresponding estimate value from the last step of the stepwise regression. Our prediction came to 0.558851 which is fairly close to our dependent variable D1 of 0.5.