Data augmentation and refinement for recommender system: A semi-supervised approach using maximum margin matrix factorization

TL;DR

This paper introduces a semi-supervised data augmentation and refinement method for collaborative filtering in recommender systems, leveraging confidence levels of predictions to improve accuracy in sparse data scenarios.

Contribution

It proposes a novel semi-supervised approach using maximum margin matrix factorization to iteratively augment and refine training data based on confidence levels.

Findings

Improved prediction accuracy across multiple CF algorithms.

Effective handling of data sparsity through confidence-based augmentation.

Enhanced recommender system performance with iterative refinement.

Abstract

Collaborative filtering (CF) has become a popular method for developing recommender systems (RSs) where ratings of a user for new items are predicted based on her past preferences and available preference information of other users. Despite the popularity of CF-based methods, their performance is often greatly limited by the sparsity of observed entries. In this study, we explore the data augmentation and refinement aspects of Maximum Margin Matrix Factorization (MMMF), a widely accepted CF technique for rating predictions, which has not been investigated before. We exploit the inherent characteristics of CF algorithms to assess the confidence level of individual ratings and propose a semi-supervised approach for rating augmentation based on self-training. We hypothesize that any CF algorithm's predictions with low confidence are due to some deficiency in the training data and hence, the performance of the algorithm can be improved by adopting a systematic data augmentation strategy. We iteratively use some of the ratings predicted with high confidence to augment the training data and remove low-confidence entries through a refinement process. By repeating this process, the system learns to improve prediction accuracy. Our method is experimentally evaluated on several state-of-the-art CF algorithms and leads to informative rating augmentation, improving the performance of the baseline approaches.