Create composite variable

haven

if (!require(haven)){
  install.packages("haven", dependencies = TRUE)
  library(haven)
}

Loading required package: haven

psych

if(!require(psych)){
  install.packages("psych", dependencies = TRUE)
  library(psych)}

Loading required package: psych

summarytools

if(!require(summarytools)){
  install.packages("summarytools", dependencies = TRUE)
  library(summarytools)}

Loading required package: summarytools

Warning in fun(libname, pkgname): couldn't connect to display ":0"

system might not have X11 capabilities; in case of errors when using dfSummary(), set st_options(use.x11 = FALSE)

Import data

dataset <- read_sav("https://osf.io/kd4ej/download")

#create dataframe with only relevant variables to work with

Extraversion <- data.frame (dataset$FFM_3, dataset$FFM_8, dataset$FFM_13, dataset$FFM_18, dataset$FFM_23, dataset$FFM_28, dataset$FFM_33, dataset$FFM_38, dataset$FFM_43)

my.keys <- make.keys(Extraversion,list(Extraversion=c(1,-2,3,-4,-5,6,7,8,-9)))

my.scales <- scoreItems (my.keys, Extraversion)

my.scores <- my.scales$scores

dataset$Extraversion <- my.scores[,]
my.scales$alpha

      Extraversion
alpha    0.7629499