This study examines model selection indices for use with dichotomous mixture item response theory (IRT) models. Five indices are considered: Akaike's information coefficient (AIC), Bayesian information coefficient (BIC), deviance information coefficient (DIC), pseudo-Bayes factor (PsBF), and posterior predictive model checks (PPMC). The five…

This review describes and evaluates a software add-in created by Frontline Systems, Inc., that can be used with Microsoft Excel 2007 to solve large, complex test assembly problems. The combination of Microsoft Excel 2007 with the Frontline Systems Premium Solver Platform is significant because Microsoft Excel is the most commonly used spreadsheet…

This study investigates whether the functions linking number-correct scores to the College-Level Examination Program (CLEP) scaled scores remain invariant over gender groups, using test data on the 16 testlet-based forms of the CLEP College Algebra exam. To be consistent with the operational practice, linking of various test forms to a common…

The partial credit model with a varying slope parameter is developed and called the generalized partial credit model (GPCM). Analysis results for simulated data by this and other polytomous item-response models demonstrate that the rating formulation of the GPCM is adaptable to the analysis of polytomous item responses. (SLD)

An ability-based guessing model is formulated and applied to several data sets regarding educational tests in language and in mathematics. The formulation of the model is such that the probability of a correct guess does not only depend on the item but also on the ability of the individual, weighted with a general discrimination parameter. By so…

Data from the California Learning Assessment System mathematics assessment were used to examine issues that arise when scores from different assessment modes are combined. Multiple-choice, open-ended, and investigation items were combined in a test across three test forms. Results illustrate the difficulties faced in evaluating combined…

Developed a procedure for defining achievement levels on continuous scales using aspects of Guttman scaling (L. Guttman, 1950) and Item Response Theory. Using data from high school mathematics tests for about 6,000 students, found the new procedure to have higher reliability, higher classification consistency, and lower classification error than…

The cognitive structure of an algebra test was defined and validated using the linear logistic test model (LLTM) and quadratic assignment (QA). A 29-item test was administered to 235 ninth graders. Results suggest the benefits of applying both LLTM and QA to test construction and analysis. (SLD)

Convergent validity of expert-systems scores for 4 complex constructed-response mathematical formats was assessed for 249 examinees from the Graduate Record Examinations (GRE) General Test in June 1989. The hypothesized five-factor model fit the data well, but an alternative with two dimensions (GRE-quantitative and constructed-response)…

The effect of multiple-choice (MC) or open-ended (OE) response format on diagnostic assessment of algebra test performance was investigated with 231 eighth and ninth graders in Tel Aviv (Israel) using bug or rule space analysis. Both analyses indicated closer similarity between parallel OE subsets than between stem-equivalent OE and MC subsets.…