One of the primary goals of international large-scale assessments in education is the comparison of country means in student achievement. This article introduces a framework for discussing differential item functioning (DIF) for such mean comparisons. We compare three different linking methods: concurrent scaling based on full invariance,…

This Monte Carlo study assessed Type I error in differential item functioning analyses using Lord's chi-square (LC), Likelihood Ratio Test (LRT), and Mantel-Haenszel (MH) procedure. Two research interests were investigated: item response theory (IRT) model specification in LC and the LRT and continuity correction in the MH procedure. This study…

In this study, whether item position effects lead to DIF in the condition where different test booklets are used was investigated. To do this the methods of Lord's chi-square and Raju's unsigned area with the 3PL model under with and without item purification were used. When the performance of the methods was compared, it was revealed that…

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…

Background: Examinees may not make enough effort when responding to test items if the assessment has no consequence for them. These disengaged responses can be problematic in low-stakes, large-scale assessments because they can bias item parameter estimates. However, the amount of bias, and whether this bias is similar across administrations, is…

Automated assessment using Natural Language Processing (NLP) has the potential to make English speaking assessments more reliable, authentic, and accessible. Yet without careful examination, NLP may exacerbate social prejudices based on gender or native language (L1). Current NLP-based assessments are prone to such biases, yet research and…

Individual response style behaviors, unrelated to the latent trait of interest, may influence responses to ordinal survey items. Response style can introduce bias in the total score with respect to the trait of interest, threatening valid interpretation of scores. Despite claims of response style stability across scales, there has been little…

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…

International large-scale assessments like international computer and information literacy study (ICILS) (Fraillon et al. in International Association for the Evaluation of Educational Achievement (IEA), 2015) provide important empirically-based knowledge through the proficiency scales, of what characterizes tasks at different difficulty levels,…

Purpose: This study aimed to examine the impact of differential item functioning in anchor items on the group invariance in test equating for different sample sizes. Within this scope, the factors chosen to investigate the group invariance in test equating were sample size, frequency of sample size of subgroups, differential form of differential…

Purpose: This study aimed to compare the performance of latent class differential item functioning (DIF) approach and IRT based DIF methods using manifest grouping. With this study, it was thought to draw attention to carry out latent class DIF studies in Turkey. The purpose of this study was to examine DIF in PISA 2015 science data set. Research…

New Meridian Corporation has developed the "Quality Testing Standards and Criteria for Comparability Claims" (QTS). The goal of the QTS is to provide guidance to states that are interested in including content from the New Meridian item bank and intend to make comparability claims with "other assessments" that include New…

New Meridian Corporation has developed the "Quality Testing Standards and Criteria for Comparability Claims" (QTS). The goal of the QTS is to provide guidance to states that are interested in including content from the New Meridian item bank and intend to make comparability claims with "other assessments" that include New…

Within polytomous items, differential item functioning (DIF) can take on various forms due to the number of response categories. The lack of invariance at this level is referred to as differential step functioning (DSF). The most common DSF methods in the literature are the adjacent category log odds ratio (AC-LOR) estimator and cumulative…

Differential item functioning (DIF), or item bias, is a relatively new concept. It has been one of the most controversial and the most studied subject in measurement theory. DIF occurs when people who have the same ability level but from different groups have a different probability of a correct response. According to Item Response Theory (IRT),…