Rasch Techniques for Detecting Bias in Performance Assessments: An Example Comparing the Performance of Native and Non-native Speakers on a Test of Academic English

Abstract

The employing of Rasch techniques for detecting biased ratings during performance assessment testing was studied. The example considered in the study was based on comparing the performance of native and non-native speakers in an academic English language test. The assessment tasks or criteria when functions differentially for particular subpopulations within a testing candidature, then the testing procedure exhibits bias in favor of a one or other group. In this regard, the susceptibility of Differential item functioning (DIF) based criteria to biased ratings, was discussed.