The aim of this study was to apply the Rasch model to an analysis of the psychometric properties of the Peabody Picture Vocabulary Test--III Form A (PPVT--IIIA) items with struggling adult readers. The PPVT--IIIA was administered to 229 African American adults whose isolated word reading skills were between third and fifth grades. Conformity of…

Type I error rates for PARSCALE's fit statistic were examined. Data were generated to fit the partial credit or graded response model, with test lengths of 10 or 20 items. The ability distribution was simulated to be either normal or uniform. Type I error rates were inflated for the shorter test length and, for the graded-response model, also for…

The crux in psychometrics is how to estimate the probability that a respondent answers an item correctly on one occasion out of many. Under the current testing paradigm this probability is estimated using all kinds of statistical techniques and mathematical modeling. Multiple evaluation is a new testing paradigm using the person's own personal…

It has been demonstrated that the individual variation in the level and rate of learning for a cohort of students over time can be estimated by hierarchical linear models. Models of this type can also be estimated using widely available structural modeling software, which provides a flexible framework for model explorations, including the use of…

The study examines the rule space model, a probabilistic model capable of measuring cognitive skill acquisition and of diagnosing erroneous rules of operation in a procedural domain. The model involves two important components: (1) determination of a set of bug distributions (bug density functions representing clusters around the rules); and (2)…