Print alpha and its confidence interval.

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Description

Print alpha and its confidence interval.

Usage

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## S3 method for class 'alpha'
summary(object, prob = 0.95,...)

Arguments

object

Results from the function cronbach.

prob

Alpha level for confidence interval. By default, the 95

...

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

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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)