Does Weighting Improve Matrix Factorization for Recommender Systems?

Fuente: arXiv
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Main Authors: Ayoub, Alex, Robertson, Samuel, Liang, Dawen, Steck, Harald, Kallus, Nathan
Format: Preprint
Published: 2025
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author Ayoub, Alex
Robertson, Samuel
Liang, Dawen
Steck, Harald
Kallus, Nathan
author_facet Ayoub, Alex
Robertson, Samuel
Liang, Dawen
Steck, Harald
Kallus, Nathan
contents Matrix factorization is a widely used approach for top-N recommendation and collaborative filtering. When implemented on implicit feedback data (such as clicks), a common heuristic is to upweight the observed interactions. This strategy has been shown to improve performance for certain algorithms. In this paper, we conduct a systematic study of various weighting schemes and matrix factorization algorithms. Somewhat surprisingly, we find that training with unweighted data can perform comparably to, and sometimes outperform, training with weighted data, especially for large models. This observation challenges the conventional wisdom. Nevertheless, we identify cases where weighting can be beneficial, particularly for models with lower capacity and specific regularization schemes. We also derive efficient algorithms for exactly minimizing several weighted objectives that were previously considered computationally intractable. Our work provides a comprehensive analysis of the interplay between weighting, regularization, and model capacity in matrix factorization for recommender systems.
format Preprint
id arxiv_https___arxiv_org_abs_2510_10440
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Does Weighting Improve Matrix Factorization for Recommender Systems?
Ayoub, Alex
Robertson, Samuel
Liang, Dawen
Steck, Harald
Kallus, Nathan
Information Retrieval
Machine Learning
Matrix factorization is a widely used approach for top-N recommendation and collaborative filtering. When implemented on implicit feedback data (such as clicks), a common heuristic is to upweight the observed interactions. This strategy has been shown to improve performance for certain algorithms. In this paper, we conduct a systematic study of various weighting schemes and matrix factorization algorithms. Somewhat surprisingly, we find that training with unweighted data can perform comparably to, and sometimes outperform, training with weighted data, especially for large models. This observation challenges the conventional wisdom. Nevertheless, we identify cases where weighting can be beneficial, particularly for models with lower capacity and specific regularization schemes. We also derive efficient algorithms for exactly minimizing several weighted objectives that were previously considered computationally intractable. Our work provides a comprehensive analysis of the interplay between weighting, regularization, and model capacity in matrix factorization for recommender systems.
title Does Weighting Improve Matrix Factorization for Recommender Systems?
topic Information Retrieval
Machine Learning
url https://arxiv.org/abs/2510.10440