library(tidyverse)
## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ dplyr     1.1.2     ✔ readr     2.1.4
## ✔ forcats   1.0.0     ✔ stringr   1.5.0
## ✔ ggplot2   3.4.2     ✔ tibble    3.2.1
## ✔ lubridate 1.9.2     ✔ tidyr     1.3.0
## ✔ purrr     1.0.1     
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag()    masks stats::lag()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors
library(EnvStats)
## 
## Attaching package: 'EnvStats'
## 
## The following objects are masked from 'package:stats':
## 
##     predict, predict.lm
## 
## The following object is masked from 'package:base':
## 
##     print.default
library(infer)
msd <- read.csv("msdlabs_race_arrest_clean.csv")
### Test self concept against IQ
iq <- lm(formula = selfconcept ~ iq, data = msd)
summary (iq)
## 
## Call:
## lm(formula = selfconcept ~ iq, data = msd)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -3.3174 -0.3213 -0.3058  0.6810  0.7158 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)    
## (Intercept) 3.2379142  0.1148582  28.191   <2e-16 ***
## iq          0.0007718  0.0011208   0.689    0.491    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.6488 on 1554 degrees of freedom
## Multiple R-squared:  0.0003051,  Adjusted R-squared:  -0.0003382 
## F-statistic: 0.4742 on 1 and 1554 DF,  p-value: 0.4911
### Calculate Cohen's f
1-.0003382
## [1] 0.9996618
.0003382/.9996618
## [1] 0.0003383144
sqrt(0.0003383144)
## [1] 0.01839332
### IQ appears to be a very weak predictor of self concept.
### Test self concept against HOUSEHOLD
hh <- lm(formula = selfconcept ~ household, data = msd)
summary (hh)
## 
## Call:
## lm(formula = selfconcept ~ household, data = msd)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -3.3018 -0.3190 -0.2947  0.6810  0.7167 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)    
## (Intercept) 3.2832862  0.0241854 135.755   <2e-16 ***
## household   0.0007137  0.0003849   1.855   0.0638 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.6482 on 1554 degrees of freedom
## Multiple R-squared:  0.002208,   Adjusted R-squared:  0.001566 
## F-statistic: 3.439 on 1 and 1554 DF,  p-value: 0.06385
### Calculate Cohen's f
1-.001566
## [1] 0.998434
.001566/.998434
## [1] 0.001568456
sqrt (0.001568456)
## [1] 0.03960374
### The conclusion is household income is a very weak predictor of self concept.
### Test self concept against schlbelong
school <- lm(formula = selfconcept ~ schlbelong, data = msd)
summary (school)
## 
## Call:
## lm(formula = selfconcept ~ schlbelong, data = msd)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -2.76379 -0.32467 -0.04423  0.67533  1.51665 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)   2.4834     0.0608   40.84   <2e-16 ***
## schlbelong    0.2804     0.0198   14.16   <2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.6107 on 1554 degrees of freedom
## Multiple R-squared:  0.1144, Adjusted R-squared:  0.1138 
## F-statistic: 200.7 on 1 and 1554 DF,  p-value: < 2.2e-16
### Calculate Cohen's f
1-.1138
## [1] 0.8862
.1138/.8862
## [1] 0.1284135
sqrt(0.1284135)
## [1] 0.3583483
### This is the strongest effect size yet. A feeling of belonging at school seems to have a 
### large positive effect on self concept. 
### Test self concept against connection to family
family <- lm(formula = selfconcept ~ famconnect, data = msd)
summary (family)
## 
## Call:
## lm(formula = selfconcept ~ famconnect, data = msd)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -2.8267 -0.2213 -0.2213  0.3840  1.1733 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  2.03746    0.06851   29.74   <2e-16 ***
## famconnect   0.39463    0.02064   19.12   <2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5839 on 1554 degrees of freedom
## Multiple R-squared:  0.1904, Adjusted R-squared:  0.1899 
## F-statistic: 365.5 on 1 and 1554 DF,  p-value: < 2.2e-16
### Calculate Cohen's f
1-.1899
## [1] 0.8101
.1899/.8101
## [1] 0.2344155
sqrt(0.2344155)
## [1] 0.4841647
### In this dataset, family connectedness appears to be the strongest predictor of self concept.