An Applied Examination of Methods for Detecting Differential Distractor Functioning

This study applied the odds-ratio (Penfield, 2008), the multinomial logistic regression (Kato et al., 2009), and the standardised distractor analysis (Schmitt and Bleistein, 1987) methods in the examination of differential distractor functioning (DDF) effects. Using data from the administration of one statewide mathematics assessment, these methods were applied to provide insight into two research questions; 1) whether the magnitude and pattern of the DDF effect is constant across all methods; 2) whether the pattern of DDF effects supports differential item functioning (DIF) findings. While some differences in results were found, all three methods present a viable option for use in improving test items included in statewide assessment programmes.