Detecting DIF for Different Language Groups on ESL Writing Assessment

The increasing interest in test fairness has resulted in a great deal of research exploring differential item functioning (DIF) in second language (L2)testing and assessment. This study investigated the extent to which descriptors of an English as a second language (ESL) writing assessment scheme functioned differentially for native Indo-European (IE) and non-Indo-European (NIE) language groups. The results of SIBTEST analysis indicated that descriptors assessing organizational effectiveness favored NIE students, while descriptors associated with grammatical knowledge favored IE students. This paper discusses the implications these findings have on developing an effective writing program for ESL learners with diverse language backgrounds.