Differential Item Functioning Among English Language Learners on a Large-Scale Mathematics Assessment

Area of Science:

• Educational Measurement
• Psychometrics
• Mathematics Education

Background:

• Significant disparities exist in mathematics achievement between English language learners (ELLs) and non-ELLs in the United States.
• Understanding the item-level sources of these achievement gaps is crucial for educational equity and competitiveness.

Purpose of the Study:

• To investigate the nature and potential sources of mathematics achievement gaps at the item level.
• To identify specific test items that may disadvantage English language learners (ELLs).

Main Methods:

• Differential item functioning (DIF) methodologies were employed, including the Mantel-Haenszel procedure, Rasch model, and Hierarchical Generalized Linear Model (HGLM).
• Analysis was conducted at the item level, providing a granular view of achievement differences.

Main Results:

• All three DIF methods consistently identified 10 common mathematics items.
• These 10 items demonstrated a bias favoring non-English language learners (non-ELLs).

Conclusions:

• The identified items suggest that language accessibility is a key factor contributing to the mathematics achievement gap.
• Recommendations are made for item writers and test developers to create more equitable assessments for ELL students.
• Findings can inform policymakers and administrators to improve middle school mathematics education in the U.S.