cronbachs_alpha {performance} | R Documentation |
Cronbach's Alpha for Items or Scales
Description
Compute various measures of internal consistencies for tests or
item-scales of questionnaires. cronbachs_alpha()
calculates the Cronbach's
Alpha value for all variables in x
. item_alpha()
is an alias for
cronbachs_alpha()
.
Usage
cronbachs_alpha(x, ...)
item_alpha(x, ...)
## S3 method for class 'data.frame'
cronbachs_alpha(x, verbose = TRUE, ...)
Arguments
x |
A matrix or a data frame, or an object of class |
... |
Currently not used. |
verbose |
Toggle warnings and messages. |
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.
Value
The Cronbach's Alpha value for x
.
Note
item_alpha()
is an alias for cronbachs_alpha()
.
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)