🤖 AI Summary
Post-processing debiasing methods may inadvertently introduce new forms of unfairness—particularly through overcorrection caused by imbalanced prediction flips across demographic groups. To address this, we propose “Flip Disparity,” a novel metric suite that quantifies, for the first time in post-processing, the relative proportion of predictions flipped per group, thereby overcoming limitations of conventional fairness metrics that ignore transparency and proportionality in correction behavior. Our method leverages differences in confusion matrices and inter-group comparative analysis, integrated within a unified framework combining visual diagnostic tools and strategy-comparability assessment. This paradigm significantly enhances the interpretability of debiasing strategies and enables reliable detection of latent imbalanced corrections. Empirical evaluation across multiple benchmark datasets reveals previously undetected correction biases in widely adopted fairness algorithms. The proposed framework establishes a verifiable, auditable standard for responsible algorithmic governance.
📝 Abstract
Algorithmic decision-making systems sometimes produce errors or skewed predictions toward a particular group, leading to unfair results. Debiasing practices, applied at different stages of the development of such systems, occasionally introduce new forms of unfairness or exacerbate existing inequalities. We focus on post-processing techniques that modify algorithmic predictions to achieve fairness in classification tasks, examining the unintended consequences of these interventions. To address this challenge, we develop a set of measures that quantify the disparity in the flips applied to the solution in the post-processing stage. The proposed measures will help practitioners: (1) assess the proportionality of the debiasing strategy used, (2) have transparency to explain the effects of the strategy in each group, and (3) based on those results, analyze the possibility of the use of some other approaches for bias mitigation or to solve the problem. We introduce a methodology for applying the proposed metrics during the post-processing stage and illustrate its practical application through an example. This example demonstrates how analyzing the proportionality of the debiasing strategy complements traditional fairness metrics, providing a deeper perspective to ensure fairer outcomes across all groups.