6 papers
RecoAtlas: From Semantic Plausibility to Set-Level Utility in LLM Recommendation Agents
Imad Aouali, Flavian Vasile, Otmane Sakhi +2
LLM recommendation agents increasingly produce structured recommendation reports: sets of items accompanied by natural-language justifications. Yet existing evaluations often reduc…
Confounding is a Pervasive Problem in Real World Recommender Systems
Alexander Merkov, David Rohde, Alexandre Gilotte +1
Unobserved confounding arises when an unmeasured feature influences both the treatment and the outcome, leading to biased causal effect estimates. This issue undermines observation…
Offline Contextual Bandit with Counterfactual Sample Identification
Alexandre Gilotte, Otmane Sakhi, Imad Aouali +1
In production systems, contextual bandit approaches often rely on direct reward models that take both action and context as input. However, these models can suffer from confounding…
Non-Linear Counterfactual Aggregate Optimization
Benjamin Heymann, Otmane Sakhi
We consider the problem of directly optimizing a non-linear function of an outcome, where this outcome itself is the sum of many small contributions. The non-linearity of the funct…
A pragmatic policy learning approach to account for users' fatigue in repeated auctions
Benjamin Heymann, Rémi Chan--Renous-Legoubin, Alexandre Gilotte
Online advertising banners are sold in real-time through auctions.Typically, the more banners a user is shown, the smaller the marginalvalue of the next banner for this user is. Th…
Maximizing the Success Probability of Policy Allocations in Online Systems
Artem Betlei, Mariia Vladimirova, Mehdi Sebbar +3
The effectiveness of advertising in e-commerce largely depends on the ability of merchants to bid on and win impressions for their targeted users. The bidding procedure is highly c…