This article aims to provide a theoretical framework for computerized adaptive tests (CAT) and item response theory models for polytomous items. Besides that, it aims to introduce the simulation and live CAT software to the related researchers. Computerized adaptive test algorithm, assumptions of item response theory models, nominal response…

This book is relevant for language testers, listening researchers, and oral proficiency teachers, in that it explores four broad themes related to the assessment of L2 listening ability: the use of authentic, real-world spoken texts; the effects of different speech varieties of listening inputs; the use of audio-visual texts; and assessing…

Cognitive assessment of young children contributes to high-stakes decisions because results are often used to determine eligibility for early intervention and special education. Previous reviews of cognitive measures for young children highlighted concerns regarding adequacy of standardization samples, steep item gradients, and insufficient floors…

This comprehensive "Handbook" focuses on the most used polytomous item response theory (IRT) models. These models help us understand the interaction between examinees and test questions where the questions have various response categories. The book reviews all of the major models and includes discussions about how and where the models…

Two strategies for assessing item bias are discussed: methods comparing item difficulties unconditional on ability and methods comparing probabilities of response conditional on ability. Results suggest that the iterative logit method is an improvement on the noniterative one and is efficient in detecting biased and unbiased items. (Author/DWH)

A model of test item dependency is presented and used to illustrate the effect that violations of local independence have on the behavior of item characteristic curves. The dependency model is flexible enough to simulate the interaction of a number of factors including item difficulty and item discrimination, varying degrees of item dependence,…

A new indicator of item difficulty, which identifies effectiveness ranges, overcomes the limitations of other item difficulty indexes in describing the difficulty of an item or a test as a whole and in aiding the selection of appropriate ability level items for a test. There are three common uses of the term "item difficulty": (1) the probability…

Concern has been expressed over the item response theory (IRT) assumption that a person's ability can be estimated in a unidimensional latent space. To examine whether or not the response to an item requires only a single latent ability, unidimensional ability estimates were compared for data generated from the multidimensional item response…

An alternative definition has been developed of the delta scale of item difficulty used at Educational Testing Service. The traditional delta scale uses an inverse normal transformation based on normal ogive models developed years ago. However, no use is made of this fact in typical uses of item deltas. It is simply one way to make the probability…

The stability of selected indices for detecting differential item performance (item bias), from one randomly equivalent sample to another, is addressed. Some recent research has criticized these indices as too unreliable for utility in measuring bias in achievement test items. Using data from a national testing of the ACT Assessment, however, this…

Rescoring of Center for Occupational and Professional Assessment objective-referenced tests is decided largely by content experts selected by client organizations. A few of the test items, statistically flagged for review, are not rescored. Some of this incongruence could be due to the use of the biserial correlation (r-biserial) as an…

The purpose of this paper is to present a generalization of the concept of item difficulty to test items that measure more than one dimension. Three common definitions of item difficulty were considered: the proportion of correct responses for a group of individuals; the probability of a correct response to an item for a specific person; and the…

Two order theoretic techniques were presented and compared. Ordering theory of Krus and Bart (1974) and an extended Takeya's item relational structure analysis (IRS) by Tatsuoka and Tatsuoka (1981) were used to extract the hierarchical item structure from three datasets. Directed graphs were constructed and both methods were assessed as to how…

The Mantel-Haenszel (MH) procedure attempts to identify and quantify differential item performance (item bias). This paper summarizes the MH statistics, and identifies the parameters they estimate. An equivalent procedure based on the Rasch model is described. The theoretical properties of the two approaches are compared and shown to require the…

The definition of differential item performance (DIP), often referred to as item bias, is discussed. DIP is suggested as a comprehensive term to encompass item bias (item invalidity which is unfair to certain population subgroups) and instructional bias (a valid reflection of group differences in instruction or background). This study investigated…