Cronbach's Alpha for Items or Scales

Compute various measures of internal consistencies for tests or item-scales of questionnaires.

Usage

cronbachs_alpha(x)

Arguments

x

A matrix or a data frame.

Value

The Cronbach's Alpha value for x.

Details

The Cronbach's Alpha value for x. A value closer to 1 indicates greater internal consistency, where usually following rule of thumb is applied to interpret the results: α < 0.5 is unacceptable, 0.5 < α < 0.6 is poor, 0.6 < α < 0.7 is questionable, 0.7 < α < 0.8 is acceptable, and everything > 0.8 is good or excellent.

References

Bland, J. M., and Altman, D. G. Statistics notes: Cronbach's alpha. BMJ 1997;314:572. 10.1136/bmj.314.7080.572

Examples

data(mtcars)
x <- mtcars[, c("cyl", "gear", "carb", "hp")]
cronbachs_alpha(x)
#> [1] 0.09463206