Two families of analysis methods can be used for differential item functioning (DIF) analysis. One family is DIF analysis based on observed scores, such as the Mantel-Haenszel (MH) and the standardized proportion-correct metric for DIF procedures; the other is analysis based on latent ability, in which the statistic is a measure of departure from…

The purpose of the present research was to study, systematically, the "goodness-of-fit" of the one-, two-, and three-parameter logistic models. We studied, using computer-simulated test data, the effects of four variables: variation in item discrimination parameters, the average value of the pseudo-chance level parameters, test length,…

The Basic Occupational Literacy Test (BOLT) was developed as an achievement test of basic skills in reading and arithmetic, for educationally disadvantaged adults. The objective was to develop a test appropriate for this population with regard to content, format, instructions, timing, norms, and difficulty level. A major issue, the use of grade…