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exametrika (version 1.1.0)

OmegaCoefficient: Omega Coefficient

Description

This function computes Tau-Congeneric Measurement, also known as McDonald's tau coefficient, for a given data set.

Usage

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

Value

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

  • OmegaCov: Omega coefficient calculated from covariance matrix

  • OmegaPhi: Omega coefficient calculated from phi coefficient matrix

  • OmegaTetrachoric: Omega coefficient calculated from tetrachoric correlation matrix

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.

References

McDonald, R. P. (1999). Test theory: A unified treatment. Erlbaum.