Investigating Differential Item Functioning of an International Mathematics Competition Items across Gender Groups

Abstract

Mathematical problem-solving competitions have existed for over a century. Scholars report the gender gap in these competitions. As a result, it is necessary to determine whether any score difference between gender groups is attributable to a genuine difference or is the result of the exam itself. Thus, the current study specifically examined bias in one of the well-known mathematics competitions: the Kangaroo Mathematics competition. Determining the fairness of Kangaroo mathematics competition items across gender groups is crucial for creating accurate comparisons and avoiding unintended construct irrelevant bias. To examine the bias, DIF analyses were conducted using Logistic Regression, Mantel-Haenszel, and Item Response Theory Likelihood Ratio Test DIF detection methods. After a series of investigations, out of 336 items, it was concluded that these mathematics items were free of DIF and bias across the gender groups. Further implications were discussed in detail regarding the validity and bias.