Lightweight yet Fine-grained: A Graph Capsule Convolutional Network with Subspace Alignment for Shared-account Sequential Recommendation

TL;DR

This paper introduces LightGC2N, a lightweight graph capsule convolutional network with subspace alignment, to improve shared-account sequential recommendation by capturing fine-grained user interactions efficiently.

Contribution

The paper proposes a novel lightweight graph capsule convolutional network with subspace alignment for more accurate and efficient shared-account sequential recommendation.

Findings

Outperforms nine state-of-the-art methods in accuracy.

Achieves better efficiency on resource-constrained devices.

Effective in capturing fine-grained user interactions.

Abstract

Shared-account Sequential Recommendation (SSR) aims to provide personalized recommendations for accounts shared by multiple users with varying sequential preferences. Previous studies on SSR struggle to capture the fine-grained associations between interactions and different latent users within the shared account's hybrid sequences. Moreover, most existing SSR methods (e.g., RNN-based or GCN-based methods) have quadratic computational complexities, hindering the deployment of SSRs on resource-constrained devices. To this end, we propose a Lightweight Graph Capsule Convolutional Network with subspace alignment for shared-account sequential recommendation, named LightGC$^2$N. Specifically, we devise a lightweight graph capsule convolutional network. It facilitates the fine-grained matching between interactions and latent users by attentively propagating messages on the capsule graphs. Besides, we present an efficient subspace alignment method. This method refines the sequence representations and then aligns them with the finely clustered preferences of latent users. The experimental results on four real-world datasets indicate that LightGC$^2$N outperforms nine state-of-the-art methods in accuracy and efficiency.