Check the internal reliability of the VVIQ, TAS-20 and its sub-scales — check_scales

Computes Cronbach's alpha and McDonald's omega for the VVIQ and the TAS-20 (total score and its three subscales - DIF, DDF, EOT), separately for each group defined by ... (e.g. per study). Expects data to contain a list-column named items, itself holding, for each group, a data frame of item-level responses with columns named vviq_q* and tas_q*.

Usage

check_scales_reliability(
  data,
  ...,
  scales = c("vviq", "tas", "dif", "ddf", "eot"),
  digits = 2,
  silence = FALSE
)

Arguments

data: A data frame with one row per group and a list-column named items, where each element is a data frame of item-level responses (columns vviq_q1...vviq_q16, tas_q1...tas_q20).
...: Grouping variables (e.g. study), used to compute reliability separately within each group.
scales: String vector with the names of the scales to examine. Has to be one or several among the defaults: "vviq", "tas", "dif", "ddf" and "eot".
digits: Number of decimal places to round the reliability coefficients to. Default is 2.
silence: Logical. If TRUE, suppresses the messages and warnings commonly emitted by psych::alpha() and psych::omega() (e.g. about reversed items or factor structure). Default is FALSE.

Value

A tibble with one row per group per scale, and columns Scale, Cronbach's alpha, McDonald's omega, plus the grouping variables passed via ....

Examples

if (FALSE) { # \dontrun{
check_scales_reliability(all_data, study)
check_scales_reliability(all_data, study, digits = 3, silence = TRUE)
} # }