11.19.2021
The meaning and measurement of bias: lessons from natural language processing – Abigail Z. Jacobs, Su Lin Blodgett, Solon Barocas, Hal Daumé, and Hanna Wallach
Proceedings of the 2020 Conference on Fairness, Accountability, and Transparency
https://dl.acm.org/doi/abs/10.1145/3351095.3375671Insights
The recent interest in identifying and mitigating bias in computational systems has introduced a wide range of different—and occasionally incomparable—proposals for what constitutes bias in such systems. This tutorial introduces the language of measurement modeling from the quantitative social sciences as a framework for examining how social, organizational, and political values enter computational systems and unpacking the varied normative concerns operationalized in different techniques for measuring “bias.” We show that this framework helps to clarify the way unobservable theoretical constructs—such as “creditworthiness,” “risk to society,” or “tweet toxicity”—are turned into measurable quantities and how this process may introduce fairness-related harms. In particular, we demonstrate how to systematically assess the construct validity and reliability of these measurements to detect and characterize specific types of harms, which arise from mismatches between constructs and their operationalizations. We then take a critical look at existing approaches to examining “bias” in NLP models, ranging from work on embedding spaces to machine translation and hate speech detection.