Instructionally Sensitive Psychometrics: Application of a New IRT-Based Detection Technique to Mathematics Achievement Test Items

Achievement modeling is carried out in groups of students characterized by heterogeneous instructional background. Extensions of item response theory models incorporate variables reflecting different amounts of opportunity-to-leam (OTL). The effects of these OTL variables are studied with respect to their influence on both the latent trait and the item performance directly. Such direct effects may reflect instructionally sensitive items. U.S. eighth-grade mathematics data from the Second International Mathematics Study are analyzed. Here, the same test is taken by students enrolled in typical instruction and students enrolled in elementary algebra classes. It is shown that the new analysis provides a more detailed way to examine the influence of instruction on responses to test items than does conventional item response theory.