cronbach.Rd
This function calculates the Cronbach alpha for one or more sets of psychometric scale items. Each item is a variable in a data frame. Each set of items is defined by a tidy selection of a set of items.
cronbach(.data, ..., .ci = 0.95)
.data | A data frame with columns that are psychometric items. |
---|---|
... | A set of comma separated tidy selectors that selects sets of
columns from |
.ci | The value of the confidence interval to calculate. |
A data frame whose rows are psychometric scales and for each scale, we have the Cronbach's alpha, and the lower and upper bound of the confidence interval on alpha.
# Return the Cronbach alpha and 95% ci for two scales. # The first scale, named `x`, is identified by all items beginning with `x_`. # The second scale, named `y`, is identified by the consecutive items from `y_1` to `y_10`. cronbach(test_psychometrics, x = starts_with('x'), y = y_1:y_10) #> # A tibble: 2 × 4 #> scale alpha ci_lo ci_hi #> <chr> <dbl> <dbl> <dbl> #> 1 x 0.620 0.452 0.788 #> 2 y 0.738 0.626 0.850