activity
20232026
collaborators
Showing cs.LGShow all

7 papers · 1 filter

cs.LG2026

Efficient Offline Learning of Ranking Policies via Top- Policy Decomposition

Ren Kishimoto, Koichi Tanaka, Haruka Kiyohara +4

Many recommender systems such as for e-commerce and news platforms aim to provide users with rankings they are likely to interact with. Off-Policy Learning (OPL) of ranking policie…

cs.LG2026

Adaptive Doubly Robust Off-Policy Evaluation for Ranking Policies under Diverse User Behavior

Kosuke Iguchi, Ren Kishimoto

Off-policy evaluation (OPE) of ranking policies is challenging be- cause selecting and ordering multiple items from a candidate set makes the number of possible rankings grow combi…

cs.LG2026

Offline Contextual Bandits in the Presence of New Actions

Ren Kishimoto, Tatsuhiro Shimizu, Kazuki Kawamura +6

Automated decision-making algorithms drive applications such as recommendation systems and search engines. These algorithms often rely on off-policy contextual bandits or off-polic…

cs.LG2026

Off-Policy Learning with Limited Supply

Koichi Tanaka, Ren Kishimoto, Bushun Kawagishi +4

We study off-policy learning (OPL) in contextual bandits, which plays a key role in a wide range of real-world applications such as recommendation systems and online advertising. T…

cs.LG2026

Beyond Match Maximization and Fairness: Retention-Optimized Two-Sided Matching

Ren Kishimoto, Rikiya Takehi, Koichi Tanaka +4

On two-sided matching platforms such as online dating and recruiting, recommendation algorithms often aim to maximize the total number of matches. However, this objective creates a…

cs.LG2023

Towards Assessing and Benchmarking Risk-Return Tradeoff of Off-Policy Evaluation

Haruka Kiyohara, Ren Kishimoto, Kosuke Kawakami +3

Off-Policy Evaluation (OPE) aims to assess the effectiveness of counterfactual policies using only offline logged data and is often used to identify the top-k promising policies fo…

cs.LG2023

SCOPE-RL: A Python Library for Offline Reinforcement Learning and Off-Policy Evaluation

Haruka Kiyohara, Ren Kishimoto, Kosuke Kawakami +3

This paper introduces SCOPE-RL, a comprehensive open-source Python software designed for offline reinforcement learning (offline RL), off-policy evaluation (OPE), and selection (OP…