Section author: Ravi Selker, Jonathon Love, Damian Dropmann

Reliability Analysis (reliability)

Description

Reliability Analysis

Usage

reliability(
  data,
  vars,
  alphaScale = TRUE,
  omegaScale = FALSE,
  meanScale = FALSE,
  sdScale = FALSE,
  corPlot = FALSE,
  alphaItems = FALSE,
  omegaItems = FALSE,
  meanItems = FALSE,
  sdItems = FALSE,
  itemRestCor = FALSE,
  revItems = NULL
)

Arguments

data	the data as a data frame
vars	a vector of strings naming the variables of interest in data
alphaScale	TRUE (default) or FALSE, provide Cronbach’s alpha
omegaScale	TRUE or FALSE (default), provide McDonald’s omega
meanScale	TRUE or FALSE (default), provide the mean
sdScale	TRUE or FALSE (default), provide the standard deviation
corPlot	TRUE or FALSE (default), provide a correlation plot
alphaItems	TRUE or FALSE (default), provide what the Cronbach’s alpha would be if the item was dropped
omegaItems	TRUE or FALSE (default), provide what the McDonald’s omega would be if the item was dropped
meanItems	TRUE or FALSE (default), provide item means
sdItems	TRUE or FALSE (default), provide item standard deviations
itemRestCor	TRUE or FALSE (default), provide item-rest correlations
revItems	a vector containing strings naming the varibales that are reverse scaled

Output

A results object containing:

results$scale	a table
results$items	a table
results$corPlot	an image

Tables can be converted to data frames with asDF or as.data.frame(). For example:

results$scale$asDF

as.data.frame(results$scale)

Examples

data('iris')

reliability(iris, vars = c('Sepal.Length', 'Sepal.Width', 'Petal.Length', 'Petal.Width'),
            omegaScale = TRUE)

#
#  RELIABILITY ANALYSIS
#
#  Scale Reliability Statistics
#  -----------------------------------------
#             Cronbach's alpha    McDonald's omega
#  -----------------------------------------
#    scale           0.708           0.848
#  -----------------------------------------
#