AlphaCoefficient {exametrika}R Documentation

Alpha Coefficient

Description

This function computes Tau-Equivalent Measurement, also known as Cronbach's alpha coefficient, for a given data set.

Usage

AlphaCoefficient(x, na = NULL, Z = NULL, w = NULL)

Arguments

x

This should be a data matrix or a Covariance/Phi/Tetrachoric matrix.

na

This parameter identifies the numbers or characters that should be treated as missing values when 'x' is a data matrix.

Z

This parameter represents a missing indicator matrix. It is only needed if 'x' is a data matrix.

w

This parameter is an item weight vector. It is only required if 'x' is a data matrix.

Value

For a correlation/covariance matrix input, returns a single numeric value representing the alpha coefficient. For a data matrix input, returns a list with three components:

AlphaCov

Alpha coefficient calculated from covariance matrix

AlphaPhi

Alpha coefficient calculated from phi coefficient matrix

AlphaTetrachoric

Alpha coefficient calculated from tetrachoric correlation matrix

References

Cronbach, L. J. (1951). Coefficient alpha and the internal structure of a test. Psychometrika, 16,297–334.


[Package exametrika version 1.5.1 Index]