Identifying Science Item Context Characteristics for English Language Learners (ELLs) and Non-ELLs by Differential Item Functioning

• In Event: Detecting and Explaining Differential Item Functioning

Abstract

This study examines item context characteristics as sources of differential item functioning (DIF) for English language learners (ELLs). Specifically, we investigate the relationship among item context characteristics, item type, and DIF statistics based on item response theory (IRT) difficulty parameters in a state fifth-grade science test. This study reveals that three item context characteristics, reading difficulty, process difficulty, and resources, were used in the items. Flagged constructed-response items generally favored ELLs, whereas flagged multiple-choice items favored non-ELLs. Content analysis of flagged items provides strong evidence of the impact of item context on students’ performance. The greater the linguistic demands, the greater are the DIF statistics favoring non-ELLs. The greater the resources, the greater are the DIF statistics favoring ELLs.

Authors

• Ting Wang, University of Washington

• Yuan-Ling Linda Liaw, University of Washington

• Min Li, University of Washington