The adequacy of equipercentile, linear, one-parameter (Rasch), and three-parameter logistic item-response theory procedures for equating 12 forms of five tests of general educational development were compared. Results indicated the equating method adequacy depends on a variety of factors such as test characteristics, equating design, and sample…

The purpose of this investigation was to examine the item characteristics of the General Educational Development Tests (GED) for specific subgroups of students. The method employed was the approach suggested by Linn and Harnisch in which the three-parameter logistic model is used for detecting interactions between item content and group…