Structured Conformal Inference for Matrix Completion with Applications to Group Recommender Systems

Fuente: arXiv
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Main Authors: Liang, Ziyi, Xie, Tianmin, Tong, Xin, Sesia, Matteo
Format: Preprint
Published: 2024
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author Liang, Ziyi
Xie, Tianmin
Tong, Xin
Sesia, Matteo
author_facet Liang, Ziyi
Xie, Tianmin
Tong, Xin
Sesia, Matteo
contents We develop a conformal inference method to construct a joint confidence region for a given group of missing entries within a sparsely observed matrix, focusing primarily on entries from the same column. Our method is model-agnostic and can be combined with any ``black-box'' matrix completion algorithm to provide reliable uncertainty estimation for group-level recommendations. For example, in the context of movie recommendations, it is useful to quantify the uncertainty in the ratings assigned by all members of a group to the same movie, enabling more informed decision-making when individual preferences may conflict. Unlike existing conformal techniques, which estimate uncertainty for one individual at a time, our method provides stronger group-level guarantees by assembling a structured calibration dataset that mimics the dependencies expected in the test group. To achieve this, we introduce a generalized weighted conformalization framework that addresses the lack of exchangeability arising from structured calibration, introducing several innovations to overcome associated computational challenges. We demonstrate the practicality and effectiveness of our approach through extensive numerical experiments and an analysis of the MovieLens 100K dataset.
format Preprint
id arxiv_https___arxiv_org_abs_2404_17561
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Structured Conformal Inference for Matrix Completion with Applications to Group Recommender Systems
Liang, Ziyi
Xie, Tianmin
Tong, Xin
Sesia, Matteo
Methodology
Machine Learning
We develop a conformal inference method to construct a joint confidence region for a given group of missing entries within a sparsely observed matrix, focusing primarily on entries from the same column. Our method is model-agnostic and can be combined with any ``black-box'' matrix completion algorithm to provide reliable uncertainty estimation for group-level recommendations. For example, in the context of movie recommendations, it is useful to quantify the uncertainty in the ratings assigned by all members of a group to the same movie, enabling more informed decision-making when individual preferences may conflict. Unlike existing conformal techniques, which estimate uncertainty for one individual at a time, our method provides stronger group-level guarantees by assembling a structured calibration dataset that mimics the dependencies expected in the test group. To achieve this, we introduce a generalized weighted conformalization framework that addresses the lack of exchangeability arising from structured calibration, introducing several innovations to overcome associated computational challenges. We demonstrate the practicality and effectiveness of our approach through extensive numerical experiments and an analysis of the MovieLens 100K dataset.
title Structured Conformal Inference for Matrix Completion with Applications to Group Recommender Systems
topic Methodology
Machine Learning
url https://arxiv.org/abs/2404.17561