The effect of guessing on the point estimate of coefficient alpha has been studied in the literature, but the impact of guessing and its interactions with other test characteristics on the interval estimators for coefficient alpha has not been fully investigated. This study examined the impact of guessing and its interactions with other test…

A latent variable modeling approach for scale reliability evaluation in heterogeneous populations is discussed. The method can be used for point and interval estimation of reliability of multicomponent measuring instruments in populations representing mixtures of an unknown number of latent classes or subpopulations. The procedure is helpful also…

An alternative derivation of Tryon's basic formula for the coefficient of domain validity or the coefficient of generalizability developed by Cronbach, Rajaratnam, and Glaser is provided. This derivation, which is also the generalized Kuder-Richardson coefficient, requires a relatively minimal number of assumptions compared with that in previously…

The effect of removing nonfunctioning items from multiple-choice tests was studied by examining change in difficulty, discrimination, and dimensionality. Results provide additional support for the benefits of eliminating nonfunctioning options, such as enhanced score reliability, reduced testing time, potential for broader domain sampling, and…

The Rasch simple logistic model is used to examine the relative item parameter values of a personality inventory with respect to populations cross-classified by sex and country. While items conform to the model within each of the populations, half the items show significant discrepancies among the populations. (Author/RL)