Identifying Test Collusion by a Method of Assessing Differential Item Functioning

• In Event: 65.079 - Roundtable Session 23
  In Roundtable Session: 65.079-18 - Methods of Detecting Response Collusion and Preknowledge

Abstract

Incidents of item compromise may lead differential item functioning (DIF) between two groups of examinees: one group who had item preknowledge and another group who did not. We modified a DIF index for identifying test results affected by item compromise. We evaluated the performance of the modified DIF index by examining detection power and Type 1 error rates. The results were compared to the performance of the person-fit index lz.

Authors

• Jiyoon Park, Federation of State Boards of Physical Therapy

• Yu Zhang, The Federation of State Boards of Physical Therapy

• Lorin Mueller, Federation of State Boards of Physical Therapy