differential item functioning.

A test item behaves differently across groups despite equal levels of the underlying trait or ability.

Use it for

Words that belong together

• test for differential item functioning
• uniform DIF
• nonuniform DIF

On the page

The team tested differential item functioning before comparing language-group scores.

Usage notes

DIF can flag possible measurement bias, but a group difference alone does not establish unfairness; interpretation requires substantive review.