cocron {cocron} R Documentation

## Statistical comparisons of n alpha coefficients

### Description

Performs a test of significance for the difference between n alpha coefficients (Cronbach, 1951). The function expects raw data input from which the alpha coefficients are calculated.

### Usage

cocron(data, dep = FALSE, standardized = FALSE, los = 0.05,
conf.level = 0.95)


### Arguments

 data A list holding two or more data.frames/matrices with rows and columns corresponding to individuals and items, respectively. From each data.frame/matrix an alpha coefficients is determined. dep A logical indicating whether the alpha coefficients are based on dependent groups of individuals standardized A logic indicating whether a standardized Cronbach alpha should be calculated (default is FALSE). los A number indicating the level of significance (default is .05). conf.level A number defining the level of confidence for the confidence intervals of the alpha coefficients (default is .95; see cronbach.alpha.CI). The confidence intervals serve as additional information only, they are not used for the test of significance.

### Details

To compare n dependent or independent alpha coefficients (Cronbach, 1951), the methods by Feldt, Woodruff, and Salih (1987) implemented in cocron.n.coefficients are used.

### Value

Returns an object of the class "cocron.n.coefficients" (see cocron.n.coefficients).

### References

Cronbach, L. J. (1951). Coefficient alpha and the internal structure of tests. Psychometrika, 16, 297-334.

Feldt, L. S., Woodruff, D. J., & Salih, F. A. (1987). Statistical inference for coefficient alpha. Applied Psychological Measurement, 11, 93-103.

### Examples


data("knowledge")

# independent alpha coefficients
cocron(knowledge, dep=FALSE)

# dependent alpha coefficients
cocron(knowledge, dep=TRUE)



[Package cocron version 1.0-1 Index]