Print alpha and its confidence interval.

Share:

Description

Print alpha and its confidence interval.

Usage

1
2
## S3 method for class 'alpha'
summary(object, prob = 0.05,...)

Arguments

object

Results from the function cronbach.

prob

Alpha level for confidence interval.

...

Option can be passed to the summary function.

Author(s)

Zhiyong Zhang and Ke-Hai Yuan

References

Zhang, Z. & Yuan, K.-H. (2013). Robust Cronbach's alpha.

Examples

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
data(holzinger)
spatial<-holzinger[, c('visual', 'cubes', 'paper', 'lozenge', 'paperrev','flagssub')]
verbal<-holzinger[, c('general', 'paragrap', 'sentence', 'wordc', 'wordm')]
speed<-holzinger[, c('add', 'code', 'counting', 'straight')]
memory<-holzinger[, c('wordr', 'numberr', 'figurer', 'object', 'numberf', 'figurew')]

alpha.spatial<-cronbach(spatial)
## diagnostic plot
plot(alpha.spatial, type='d')

## alpha with varphi=.01 & standard error
alpha.spatial<-cronbach(spatial, varphi=.01, se=TRUE)
## confidence interval
summary(alpha.spatial)