Creating Composite Variables

Load Packages

haven

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

psych

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

summarytools

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

Import Data

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

Scoring Variable

Dataframe

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

List of ‘keys’.

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.spss.web$Extraversion <- Extraversion.scores[,]

Print the cronbach alpha

Extraversion.scales$alpha

      Extraversion
alpha    0.8141661