Create composite variable

Load Packages

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

Loading required package: haven

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

Loading required package: psych

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

Scoring Variable

#create dataframe with only relevant variables to work with

Extraversion <- data.frame (dataset$FFM_1, dataset$FFM_6, dataset$FFM_11, dataset$FFM_16, dataset$FFM_21, dataset$FFM_26, dataset$FFM_31, dataset$FFM_36)

#create list of ‘keys’. The numbers just refer to the order of the question in the data.frame() you just made. The most important thing is to mark the questions that should be reversed scored with a ‘-’. Extraversion.keys <- make.keys(Extraversion, list(Extraversion=c(1,-2,3,4,-5,6,-7,8)))

#score the scale Extraversion.scales <- scoreItems (Extraversion.keys, Extraversion)

#save the scores Extraversion.scores <- Extraversion.scales$scores

#save the scores back in ‘dataset’ dataset$Extraversion <- Extraversion.scores[,]

#print the cronbach alpha Extraversion.scales$alpha