Simulation Evaluating Disproportionality-Based Indicators of Inequitable Selection Practices Into Advanced Academic Programming

Gifted education programs identify students with exceptional ability or potential and provide specialized educational interventions to develop general academic and domain-specific talent. Research and legal actions have found access to gifted education riddled with inequity. Indicators of inequity in selection practices based on disproportionality have been developed in the context of employment and gifted education; however, these indicators have not been compared side by side. We evaluate combinations of disproportionality-based metrics and thresholds on their ability to flag for inequity those selection practices that are indeed inequitable while not flagging for inequity those that are not. Specifically, the risk ratio and a generalized form of the Inequity Allowance Formula/Inequity Index, called here the inequity allowance ratio, are evaluated with thresholds between 0.1 and 0.9. We evaluate false-positive rates and true-positive rates when equity or inequity in selection practices exists. Furthermore, we explore the effect of program selectivity on the performance of these indicators. Ultimately, we find that recommendations regarding which disproportionality-based metric and threshold to use depends on factors that we cannot know, including the distribution of qualification of students and the quantifiable selectivity of a program. Therefore, the use of a disproportionality-based indicator when evaluating programs for potential inequity is not recommended.