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…

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…

The purpose of this study was to evaluate the combined effects of reduced equating sample size and shortened anchor test length on item response theory (IRT)-based linking and equating results. Data from two independent operational forms of a large-scale testing program were used to establish the baseline results for evaluating the results from…

We examined the appropriateness of the anchor composition in a mixed-format test, which includes both multiple-choice (MC) and constructed-response (CR) items, using subpopulation invariance indices. We derived linking functions in the nonequivalent groups with anchor test (NEAT) design using two types of anchor sets: (a) MC only and (b) a mix of…

This study examined variations of the nonequivalent-groups equating design for mixed-format tests--tests containing both multiple-choice (MC) and constructed-response (CR) items--to determine which design was most effective in producing equivalent scores across the two tests to be equated. Four linking designs were examined: (a) an anchor with…

This study examined variations of a nonequivalent groups equating design used with constructed-response (CR) tests to determine which design was most effective in producing equivalent scores across the two tests to be equated. Using data from a large-scale exam, the study investigated the use of anchor CR item rescoring in the context of classical…

A single group (SG) equating design with nearly equivalent test forms (SiGNET) design was developed by Grant (2006) to equate small volume tests. The basis of this design is that examinees take two largely overlapping test forms within a single administration. The scored items for the operational form are divided into mini-tests called testlets.…

The purpose of this paper is to explore methods to approximate population invariance without conducting multiple linkings for subpopulations. Under the single group or equivalent groups design, no linking needs to be performed for the parallel-linear system linking functions. The unequated raw score information can be used as an approximation. For…

Randomly equivalent forms (REF) of tests in listening and reading for nonnative speakers of English were created by stratified random assignment of items to forms, stratifying on item content and predicted difficulty. The study included 50 replications of the procedure for each test. Each replication generated 2 REFs. The equivalence of those 2…

This study applied kernel equating (KE) in two scenarios: equating to a very similar population and equating to a very different population, referred to as a distant population, using SAT® data. The KE results were compared to the results obtained from analogous classical equating methods in both scenarios. The results indicate that KE results are…

This report builds on and extends existent research on population invariance to new tests and issues. The authors lay the foundation for a deeper understanding of the use of population invariance measures in a wide variety of practical contexts. The invariance of linear, equipercentile and IRT equating methods are examined using data from five…