Naver Labs Europe at TREC 2020 Fair Ranking Track

In our participation to the TREC 2020 Fair Ranking Track, as Naver Labs Europe, we focused on the re-ranking task and we investigated the performance of a controller as a way to minimize unfairness over time, with minimal loss of utility. We used a two-step approach, based on (1) a relevance probability estimator, and (2) a controller that aims to bring the actual exposure close to the target exposure. This paper describes the components we designed in more detail. It contains a comparison of the performance of the controller to a baseline, which consists of a Plackett-Luce sampler. It also analyses the effect of the quality of the estimated relevance probabilities (closeness to the true binary relevance values) on the controller performance.