Scenario 6.3

Scenario 6.3 Mindfulness Stress

library(readxl)
library(effectsize)
library(rstatix)

## 
## Attaching package: 'rstatix'

## The following objects are masked from 'package:effectsize':
## 
##     cohens_d, eta_squared

## The following object is masked from 'package:stats':
## 
##     filter

Dataset6_3 <- read_excel("C:/Users/Mrlaz/Downloads/Dataset6.3.xlsx")

Before <- Dataset6_3$Stress_Pre
After  <- Dataset6_3$Stress_Post

Differences <- After - Before

mean(Before); median(Before); sd(Before)

## [1] 65.86954

## [1] 67.33135

## [1] 9.496524

mean(After); median(After); sd(After)

## [1] 57.90782

## [1] 59.14539

## [1] 10.1712

hist(Differences, col="blue", main="Difference Scores")

boxplot(Differences, col="blue")

shapiro.test(Differences)

## 
##  Shapiro-Wilk normality test
## 
## data:  Differences
## W = 0.95612, p-value = 0.1745

t.test(Before, After, paired=TRUE)

## 
##  Paired t-test
## 
## data:  Before and After
## t = 3.9286, df = 34, p-value = 0.0003972
## alternative hypothesis: true mean difference is not equal to 0
## 95 percent confidence interval:
##   3.843113 12.080317
## sample estimates:
## mean difference 
##        7.961715

wilcox.test(Before, After, paired=TRUE)

## 
##  Wilcoxon signed rank exact test
## 
## data:  Before and After
## V = 518, p-value = 0.0005508
## alternative hypothesis: true location shift is not equal to 0

cohens_d(Stress_Post ~ Stress_Pre,
         data = Dataset6_3,
         paired = TRUE)

## # A tibble: 595 × 7
##    .y.         group1           group2           effsize    n1    n2 magnitude
##  * <chr>       <chr>            <chr>              <dbl> <int> <int> <ord>    
##  1 Stress_Post 41.6906882541988 49.6958783027338      NA     1     1 <NA>     
##  2 Stress_Post 41.6906882541988 53.4656051466686      NA     1     1 <NA>     
##  3 Stress_Post 41.6906882541988 53.7967257510268      NA     1     1 <NA>     
##  4 Stress_Post 41.6906882541988 54.2776119794539      NA     1     1 <NA>     
##  5 Stress_Post 41.6906882541988 56.9532831578635      NA     1     1 <NA>     
##  6 Stress_Post 41.6906882541988 57.4198472087007      NA     1     1 <NA>     
##  7 Stress_Post 41.6906882541988 57.8796143506825      NA     1     1 <NA>     
##  8 Stress_Post 41.6906882541988 59.4808533383599      NA     1     1 <NA>     
##  9 Stress_Post 41.6906882541988 60.2531530410475      NA     1     1 <NA>     
## 10 Stress_Post 41.6906882541988 62.2201508620985      NA     1     1 <NA>     
## # ℹ 585 more rows

df_long <- data.frame(
  id=rep(1:length(Before),2),
  time=rep(c("Before","After"),each=length(Before)),
  score=c(Before,After)
)

wilcox_effsize(df_long, score~time, paired=TRUE)

## # A tibble: 1 × 7
##   .y.   group1 group2 effsize    n1    n2 magnitude
## * <chr> <chr>  <chr>    <dbl> <int> <int> <ord>    
## 1 score After  Before   0.562    35    35 large

Difference normality p = 0.175 → normal Use Dependent (paired) t-test Means Before: M = 65.87, SD = 9.50 After: M = 57.91, SD = 10.17 Test t(34) = 3.93 p < .001

There was a significant reduction in stress levels between before the mindfulness program (M = 65.87, SD = 9.50) and after the program (M = 57.91, SD = 10.17), t(34) = 3.93, p < .001