Title
Density-Ratio Based Personalised Ranking from Implicit Feedback
Abstract
ABSTRACT Learning from implicit user feedback is challenging as we can only observe positive samples but never access negative ones. Most conventional methods cope with this issue by adopting a pairwise ranking approach with negative sampling. However, the pairwise ranking approach has a severe disadvantage in the convergence time owing to the quadratically increasing computational cost with respect to the sample size; it is problematic, particularly for large-scale datasets and complex models such as neural networks. By contrast, a pointwise approach does not directly solve a ranking problem, and is therefore inferior to a pairwise counterpart in top-K ranking tasks; however, it is generally advantageous in regards to the convergence time. This study aims to establish an approach to learn personalised ranking from implicit feedback, which reconciles the training efficiency of the pointwise approach and ranking effectiveness of the pairwise counterpart. The key idea is to estimate the ranking of items in a pointwise manner; we first reformulate the conventional pointwise approach based on density ratio estimation and then incorporate the essence of ranking-oriented approaches (e.g. the pairwise approach) into our formulation. Through experiments on three real-world datasets, we demonstrate that our approach dramatically reduces the convergence time (one to two orders of magnitude faster) and significantly improves the ranking performance.
Year
DOI
Venue
2021
10.1145/3442381.3450027
International World Wide Web Conference
Keywords
DocType
Citations 
personalised recommendation, collaborative filtering, implicit feedback, learning to rank, semi-supervised learning
Conference
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Riku Togashi113.74
Masahiko Kato2103.98
Mayu Otani3398.40
Shin'ichi Satoh473.83