Untitled

library(tidyverse)

## Warning: package 'tidyverse' was built under R version 4.5.3

## Warning: package 'lubridate' was built under R version 4.5.3

## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ dplyr     1.1.4     ✔ readr     2.1.6
## ✔ forcats   1.0.1     ✔ stringr   1.6.0
## ✔ ggplot2   4.0.1     ✔ tibble    3.3.0
## ✔ lubridate 1.9.5     ✔ tidyr     1.3.2
## ✔ purrr     1.2.0     
## ── 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(lsr)
library(car)

## Warning: package 'car' was built under R version 4.5.3

## Zorunlu paket yükleniyor: carData

## Warning: package 'carData' was built under R version 4.5.3

## 
## Attaching package: 'car'

## The following object is masked from 'package:dplyr':
## 
##     recode

## The following object is masked from 'package:purrr':
## 
##     some

set.seed(1923) #Tekrarlanabilirlik için
deney_grubu<-rnorm(50, mean = 45, sd=8) #ilaç verilen grup(deney grubu)
kontrol_grubu<- rnorm(50, mean = 53, sd=8) #plasebo verilen grup(kontrol grubu)

fare_verisi<-data.frame(grup=rep(c("deney", "kontrol"),each=50)) %>% 
  mutate(sure= round(c(deney_grubu,
                       kontrol_grubu),2))

head(fare_verisi)

##    grup  sure
## 1 deney 39.81
## 2 deney 45.56
## 3 deney 53.49
## 4 deney 56.08
## 5 deney 52.47
## 6 deney 42.59

tail(fare_verisi)

##        grup  sure
## 95  kontrol 47.23
## 96  kontrol 60.74
## 97  kontrol 53.52
## 98  kontrol 51.93
## 99  kontrol 63.96
## 100 kontrol 65.11

fare_istatistik<-fare_verisi %>% 
  group_by(grup) %>% 
  summarise(N=n(),
            ortalama=mean(sure),
            standart_sapma=sd(sure))
print(fare_istatistik)

## # A tibble: 2 × 4
##   grup        N ortalama standart_sapma
##   <chr>   <int>    <dbl>          <dbl>
## 1 deney      50     45.2           8.81
## 2 kontrol    50     53.4           7.92

# Her grup için ayrı ayrı normallik testi
fare_verisi %>% 
  group_by(grup) %>% 
  summarise(shapiro_p=
              shapiro.test(sure)$p.value)

## # A tibble: 2 × 2
##   grup    shapiro_p
##   <chr>       <dbl>
## 1 deney       0.409
## 2 kontrol     0.810

leveneTest(sure~grup, data = fare_verisi)

## Warning in leveneTest.default(y = y, group = group, ...): group coerced to
## factor.

## Levene's Test for Homogeneity of Variance (center = median)
##       Df F value Pr(>F)
## group  1  0.5295 0.4686
##       98

sonuc<-t.test(sure~grup, data = fare_verisi,
              var.equal= TRUE)
print(sonuc)

## 
##  Two Sample t-test
## 
## data:  sure by grup
## t = -4.9393, df = 98, p-value = 3.227e-06
## alternative hypothesis: true difference in means between group deney and group kontrol is not equal to 0
## 95 percent confidence interval:
##  -11.601619  -4.951181
## sample estimates:
##   mean in group deney mean in group kontrol 
##               45.1614               53.4378

# cohen's d (Etki Büyüklüğü)
cohensD(sure~grup, data = fare_verisi)

## [1] 0.9878595

yapılan bağımsız örneklem t-testi sonucunda, ilaç verilen deney grubunun labirent tamamlama sürelerinin (x=46.15, ss=8.81), kontrol grubuna göre (x=52.44, ss=7.92) anlamlı derecede daha düşük (hızlı) olduğunu saptamıştır, t(98)=-4.34,p<.001, d=0.87. Bu bulgu, ilaç -x’in mekansal bellek ve öğrenme üzerinde geliştirici bir etkisi olduğunu desteklemektedir.