Position-aware Graph Transformer for Recommendation

TL;DR

This paper introduces PGTR, a position-aware graph transformer that combines global and local features for improved recommendation accuracy, especially in sparse and noisy interaction data.

Contribution

It proposes a novel graph transformer framework that explicitly incorporates node positional information to enhance collaborative filtering signals.

Findings

PGTR outperforms existing GCN-based methods on four real-world datasets.

The model is robust against data sparsity and noise.

Incorporating positional encodings improves recommendation quality.

Abstract

Collaborative recommendation fundamentally involves learning high-quality user and item representations from interaction data. Recently, graph convolution networks (GCNs) have advanced the field by utilizing high-order connectivity patterns in interaction graphs, as evidenced by state-of-the-art methods like PinSage and LightGCN. However, one key limitation has not been well addressed in existing solutions: capturing long-range collaborative filtering signals, which are crucial for modeling user preference. In this work, we propose a new graph transformer (GT) framework -- \textit{Position-aware Graph Transformer for Recommendation} (PGTR), which combines the global modeling capability of Transformer blocks with the local neighborhood feature extraction of GCNs. The key insight is to explicitly incorporate node position and structure information from the user-item interaction graph into GT architecture via several purpose-designed positional encodings. The long-range collaborative signals from the Transformer block are then combined linearly with the local neighborhood features from the GCN backbone to enhance node embeddings for final recommendations. Empirical studies demonstrate the effectiveness of the proposed PGTR method when implemented on various GCN-based backbones across four real-world datasets, and the robustness against interaction sparsity as well as noise.