In typical differential item functioning (DIF) assessments, an item's DIF status is not influenced by its status in previous test administrations. An item that has shown DIF at multiple administrations may be treated the same way as an item that has shown DIF in only the most recent administration. Therefore, much useful information about the…

An odds ratio approach (ORA) under the framework of a nested logit model was proposed for evaluating differential distractor functioning (DDF) in multiple-choice items and was compared with an existing ORA developed under the nominal response model. The performances of the two ORAs for detecting DDF were investigated through an extensive…

This article introduces longitudinal multistage testing (lMST), a special form of multistage testing (MST), as a method for adaptive testing in longitudinal large-scale studies. In lMST designs, test forms of different difficulty levels are used, whereas the values on a pretest determine the routing to these test forms. Since lMST allows for…

Analyzing examinees' responses using cognitive diagnostic models (CDMs) has the advantage of providing diagnostic information. To ensure the validity of the results from these models, differential item functioning (DIF) in CDMs needs to be investigated. In this article, the Wald test is proposed to examine DIF in the context of CDMs. This study…

Trend estimation in international comparative large-scale assessments relies on measurement invariance between countries. However, cross-national differential item functioning (DIF) has been repeatedly documented. We ran a simulation study using national item parameters, which required trends to be computed separately for each country, to compare…

Using data from a large-scale exam, in this study we compared various designs for equating constructed-response (CR) tests to determine which design was most effective in producing equivalent scores across the two tests to be equated. In the context of classical equating methods, four linking designs were examined: (a) an anchor set containing…

This study demonstrated the equivalence between the Rasch testlet model and the three-level one-parameter testlet model and explored the Markov Chain Monte Carlo (MCMC) method for model parameter estimation in WINBUGS. The estimation accuracy from the MCMC method was compared with those from the marginalized maximum likelihood estimation (MMLE)…

In this paper we present a new methodology for detecting differential item functioning (DIF). We introduce a DIF model, called the random item mixture (RIM), that is based on a Rasch model with random item difficulties (besides the common random person abilities). In addition, a mixture model is assumed for the item difficulties such that the…

This study addressed the sampling error and linking bias that occur with small samples in a nonequivalent groups anchor test design. We proposed a linking method called the synthetic function, which is a weighted average of the identity function and a traditional equating function (in this case, the chained linear equating function). Specifically,…

Six statistical methods for identifying possible sources of bias in standardized test items are presented. The relationship between chi-squared methods and item-response theory methods are also discussed. (Author/BW)

Two problems in the investigation of predictive bias in tests, the effect of unreliability of the predictors, and the effect of excluding a predictor from the regression equation on which there are preexisting group differences, are discussed. (Author)

With regard to the DeFunis vs. Odegaard law school admission discrimination case, selection models were applied to hypothetical situations based upon evidence in the literature concerning such matters as mean differences between majority and minority groups on predictors and criteria, slopes of the within group regression lines, and correlations…

Biased test items were intentionally imbedded within a test and administered to large samples of Black and White college students. Three item bias detection methods (the three-parameter item characteristic curve procedure, the chi-square method, and the transformed item difficulty approach) were applied to the data. (Author/PN)

Test data from two diverse culture groups were analyzed to determine the agreement among four methods of detecting item bias (transformed difficulty, discrimination differences, chi-square, and item characteristic curve). The test battery contained 155 items from six subtests: vocabulary, reading comprehension, mathematics, letter groups,…