Empirical information regarding performance of model-fit procedures has been a persistent need in measurement practice. Statistical procedures for evaluating item fit were applied to real test examples that consist of both dichotomously and polytomously scored items. The item fit statistics used in this study included the PARSCALE's G[squared],…

Much has been written concerning the potential group differences in responding to multiple-choice achievement test items. This discussion has included references to possible disparities in tendency to omit such test items. When test scores are used for high-stakes decision making, even small differences in scores and rankings that arise from male…

The interaction of reading and computational abilities in solving mathematics word problems was investigated with the responses of about 20,000 fourth graders and 20,000 eighth graders to items from the Iowa Tests of Basic Skills. Item responses exhibited different types of interaction, a finding with implications for item-response theory…