What’s in a Topic? Exploring the Interaction Between Test-taker Age and Item Content in High-Stakes Testing

The research reported in this article investigates differential item functioning (DIF) in a listening comprehension test. The study explores the relationship between test-taker age and the items’ language domains across multiple test forms. The data comprise test-taker responses (N = 2861) to a total of 133 unique items, 46 items of which were shared across two or more forms. Twenty-one items demonstrated DIF. However, there was no pattern by language domain. Eleven items showing DIF appeared in more than one test form but DIF for these items occurred only once.