cocron {cocron} | R Documentation |
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.
cocron(data, dep = FALSE, standardized = FALSE, los = 0.05,
conf.level = 0.95)
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 |
conf.level |
A number defining the level of confidence for the confidence intervals of the alpha coefficients (default is |
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.
Returns an object of the class "cocron.n.coefficients
" (see cocron.n.coefficients).
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.
cocron.n.coefficients, cocron.two.coefficients
data("knowledge")
# independent alpha coefficients
cocron(knowledge, dep=FALSE)
# dependent alpha coefficients
cocron(knowledge, dep=TRUE)