Investigating Grade-Level Differential Item Functioning With an Adaptive English Language Arts Assessment: A Perspective of Measurement Invariance

• In Event: Marriott Roundtable Session 35
  In Roundtable Session: Differential Item Functioning

Abstract

This study capitalizes on a rich set of data from a large-scale computer-delivered, K-12 adaptive ELA assessment to investigate the issue of grade-level differential item functioning. Using both a statistical significance test and measure of effect size, equated item difficulties are compared for the same items administered across multiple grade levels from grade 3 to grade 10. Findings indicate there is a large lack of measurement invariance that exists within a CAT environment where across-grade item administration is allowed. The level of grade-level DIF that was calculated arguably can affect the validity of reported test scores if not reasonably accounted for by the adaptive algorithm.

Author

• John N. Denbleyker, Houghton Mifflin Harcourt