Two discrimination coefficients, known as "disco" and "odisco," are proposed for measuring the extent of overlap in distributions as a direct function of the variance between the arithmetic means. These coefficients are related to K. Pearson's "eta" (1905) and R. A. Fisher's "F" (1950). (SLD)

The work presented in this paper defined conceptually the concepts of multidimensional discrimination and information, derived mathematical expressions for the concepts for a particular multidimensional item response theory (IRT) model, and applied the concepts to actual test data. Multidimensional discrimination was defined as a function of the…

This study develops a weighted least squares method for transforming a logistic scale in such a way that the estimates of ability parameters on the tranformed scale are as comparable as possible with those on another scale. This scale tranformation process is referred to as equating of scales. Equating is an important procedure in studies…