This study evaluated the impact of subgroup weighting for equating through a common-item anchor. We used data from a single test form to create two research forms for which the equating relationship was known. The results showed that equating was most accurate when the new form and reference form samples were weighted to be similar to the target…

Equating the scores from different forms of a test requires collecting data that link the forms. Problems arise when the test forms to be linked are given to groups that are not equivalent and the forms share no common items by which to measure or adjust for this group nonequivalence. We compared three approaches to adjusting for group…

The purpose of this study was to evaluate the effectiveness of linking test scores by using test takers' background data to form pseudo-equivalent groups (PEG) of test takers. Using 4 operational test forms that each included 100 items and were taken by more than 30,000 test takers, we created 2 half-length research forms that had either 20…

The purpose of this simulation study was to assess the accuracy of a classical test theory (CTT)-based procedure for estimating the alternate-forms reliability of scores on a multistage test (MST) having 3 stages. We generated item difficulty and discrimination parameters for 10 parallel, nonoverlapping forms of the complete 3-stage test and…

The purpose of this study was to investigate the potential impact of misrouting under a 2-stage multistage test (MST) design, which includes 1 routing and 3 second-stage modules. Simulations were used to create a situation in which a large group of examinees took each of the 3 possible MST paths (high, middle, and low). We compared differences in…

This study examines the use of subpopulation invariance indices to evaluate the appropriateness of using a multiple-choice (MC) item anchor in mixed-format tests, which include both MC and constructed-response (CR) items. Linking functions were derived in the nonequivalent groups with anchor test (NEAT) design using an MC-only anchor set for 4…

This paper describes an empirical evaluation of a Bayesian procedure for equating scores on test forms taken by small numbers of examinees, using collateral information from the equating of other test forms. In this procedure, a separate Bayesian estimate is derived for the equated score at each raw-score level, making it unnecessary to specify a…