The Role of Anchor Block Item Difficulty Spread on Scale Stability

• In Event: Approaches to Scaling, Equating, and Linking

Abstract

This study investigates the relationship of the total and anchor test correlation in a sequence of equatings and the amount of scale drift. This study builds on the Sinharay/Holland midi-test idea (Sinharay & Holland, 2007) for building anchor tests to an on-going testing program. By controlling for the item difficulty spread of the anchor tests (Sinharay & Holland, 2006) we will create chains of test forms with varying anchor-test and total-test correlations.

Authors

• Thomas P. Proctor, The College Board

• Judit Antal, The College Board

• Gerald J. Melican, The College Board