Recent research provides evidence that an intersectional approach to defining reference and focal groups results in a higher percentage of comparisons flagged for potential DIF. The study presented here examined the generalizability of this pattern across methods for examining DIF. While the level of DIF detection differed among the four methods…

The purpose of this ITEMS module is to provide an introduction to differential item functioning (DIF) analysis using mixture item response models. The mixture item response models for DIF analysis involve comparing item profiles across latent groups, instead of manifest groups. First, an overview of DIF analysis based on latent groups, called…

This article illustrates five different methods for estimating Angoff cut scores using item response theory (IRT) models. These include maximum likelihood (ML), expected a priori (EAP), modal a priori (MAP), and weighted maximum likelihood (WML) estimators, as well as the most commonly used approach based on translating ratings through the test…

Evidence of comparability is generally needed whenever there are variations in the conditions of an assessment administration, including variations introduced by the administration of an assessment on multiple digital devices (e.g., tablet, laptop, desktop). This article is meant to provide a comprehensive examination of issues relevant to the…

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…

A variety of differential item functioning (DIF) methods have been proposed and used for ensuring that a test is fair to all test takers in a target population in the situations of, for example, a test being translated to other languages. However, once a method flags an item as DIF, it is difficult to conclude that the grouping variable (e.g.,…

There is no comprehensive database of U.S. district-level test scores that is comparable across states. We describe and evaluate a method for constructing such a database. First, we estimate linear, reliability-adjusted linking transformations from state test score scales to the scale of the National Assessment of Educational Progress (NAEP). We…

The purpose of this study is to investigate the impact of discrete anchor items versus passage-based anchor items on observed score equating using empirical data.This study compares an "SAT"® critical reading anchor that contains more discrete items proportionally, compared to the total tests to be equated, to another anchor that…

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…

A Monte Carlo study was conducted to examine the accuracy of differential item functioning (DIF) detection using the differential functioning of items and tests (DFIT) method. Specifically, the performance of DFIT was compared using "testwide" critical values suggested by Flowers, Oshima, and Raju, based on simulations involving large numbers of…

Even if national and international assessments are designed to be comparable, subsequent psychometric analyses often reveal differential item functioning (DIF). Central to achieving comparability is to examine the presence of DIF, and if DIF is found, to investigate its sources to ensure differentially functioning items that do not lead to bias.…

The paper reports on the adaptation of a D-KEFS test battery for Slovakia. Drawing on concrete examples, it describes and illustrates the key issues relating to the transfer of test items from one socio-cultural environment to another. The standardisation sample of the population of Slovak pupils in the fourth year of primary school included 250…

Current methods for detecting growth of students' problem-solving skills in math focus mainly on analyzing changes in test scores. Score-level analysis, however, may fail to reflect subtle changes that might be evident at the item level. This article demonstrates a method for studying item-level changes using data from a multiwave experiment with…

We present an extension of the logistic regression procedure to identify dichotomous differential item functioning (DIF) in the presence of more than two groups of respondents. Starting from the usual framework of a single focal group, we propose a general approach to estimate the item response functions in each group and to test for the presence…

Research Findings: This study examined the measurement equivalence of the "Teaching Strategies GOLD[R]" assessment system across subgroups of children based on their primary language and disability status. This study is based on teacher-collected assessment data for 3-, 4-, and 5-year-old children for the fall of 2010, winter of 2010, and spring…