Unbiased Recommender Learning from Implicit Feedback via Weakly Supervised Learning
Hao Wang, Zhichao Chen, Haotian Wang, Yanchao Tan, Licheng Pan, Tianqiao Liu, Xu Chen, Haoxuan Li
Abstract
Implicit feedback recommendation is challenged by the missing negative feedback essential for effective model training. Existing methods often resort to negative sampling, a technique that assumes unlabeled interactions as negative samples. This assumption risks misclassifying potential positive samples within the unlabeled data, thereby undermining model performance. To address this issue, we introduce PURL, a model-agnostic framework that reframes implicit feedback recommendation as a weakly supervised learning task, eliminating the need for negative samples. However, its unbiasedness hinges on the accurate estimation of the class prior. To address this challenge, we propose Progressive Proximal Transport (PPT), which estimates the class prior by minimizing the proximal transport cost between positive and unlabeled samples. Experiments on three real-world datasets validate the efficacy of PURL in terms of improved recommendation quality. Code is available at https://github.com/HowardZJU/weakrec.
BibTeX
@inproceedings{
wang2025unbiased,
title={Unbiased Recommender Learning from Implicit Feedback via Weakly Supervised Learning},
author={Hao Wang and Zhichao Chen and Haotian Wang and Yanchao Tan and Licheng Pan and Tianqiao Liu and Xu Chen and Haoxuan Li and Zhouchen Lin},
booktitle={Forty-second International Conference on Machine Learning},
year={2025},
url={https://openreview.net/forum?id=0E5rZOGA13}
}