Papers › Reducing Disparate Exposure in Ranking: A Learning To Rank Approach

Reducing Disparate Exposure in Ranking: A Learning To Rank Approach

22 May 2018arXiv:1805.08716links table onlyarchive 2025-07-28

Meike Zehlike, Carlos Castillo

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Ranked search results have become the main mechanism by which we find content, products, places, and people online. Thus their ordering contributes not only to the satisfaction of the searcher, but also to career and business opportunities, educational placement, and even social success of those being ranked. Researchers have become increasingly concerned with systematic biases in data-driven ranking models, and various post-processing methods have been proposed to mitigate discrimination and inequality of opportunity. This approach, however, has the disadvantage that it still allows an unfair ranking model to be trained. In this paper we explore a new in-processing approach: DELTR, a learning-to-rank framework that addresses potential issues of discrimination and unequal opportunity in rankings at training time. We measure these problems in terms of discrepancies in the average group exposure and design a ranker that optimizes search results in terms of relevance and in terms of reducing such discrepancies. We perform an extensive experimental study showing that being "colorblind" can be among the best or the worst choices from the perspective of relevance and exposure, depending on how much and which kind of bias is present in the training set. We show that our in-processing method performs better in terms of relevance and exposure than a pre-processing and a post-processing method across all tested scenarios.

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MilkaLichtblau/BA_Laura mentioned on GitHub report
MilkaLichtblau/DELTR-Experiments mentioned on GitHubGPL-3.0 report
fair-search/fairsearch-deltr-java mentioned on GitHubNOASSERTION report
fair-search/fairsearchdeltr-java mentioned on GitHubNOASSERTION report
fair-search/fairsearchdeltr-python mentioned on GitHubApache-2.0 report

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1ran · our draft was wrong
4unverified

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prepare_data fair-search/fairsearch-deltr-python/fairsearchdeltr/deltr.py community (archive-listed) ran · our draft was wrong Apache-2.0 (permissive) · 526319b0136b57a6 · report
find_items_per_group_per_query fair-search/fairsearchdeltr-python/fairsearchdeltr/trainer.py community (archive-listed) unverified Apache-2.0 (permissive) · dc6b97d3fd7029d6 · report
normalized_exposure fair-search/fairsearchdeltr-python/fairsearchdeltr/trainer.py community (archive-listed) unverified Apache-2.0 (permissive) · 8e623e96e250df87 · report
normalized_topp_prot_deriv_per_group fair-search/fairsearchdeltr-python/fairsearchdeltr/trainer.py community (archive-listed) unverified Apache-2.0 (permissive) · 51ee7554594db825 · report
singleton fair-search/fairsearch-deltr-for-elasticsearch/utils.py community (archive-listed) unverified Apache-2.0 (permissive) · 20b09647f7a56e44 · report

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