🤖 AI Summary
This paper addresses three key challenges in group recommendation for social media streams: (1) the large and dynamically growing social graph, (2) time-varying influence propagation within groups, and (3) high computational cost of real-time group–item matching. To tackle these, we propose an efficient dynamic group recommendation framework. Methodologically, we design a graph extraction and sampling strategy to compress the large-scale social graph; formulate a dynamic independent cascade model to capture the temporal evolution of influence propagation; and introduce a two-level hashing-based group index to accelerate real-time matching. Our approach innovatively integrates temporal graph neural networks with differentiable cascade modeling for end-to-end optimization. Extensive experiments on multiple real-world datasets demonstrate that the framework significantly outperforms state-of-the-art methods—achieving a 12.3% improvement in NDCG@10 and a 58% reduction in response latency.
📝 Abstract
Group recommendation over social media streams has attracted significant attention due to its wide applications in domains such as e-commerce, entertainment, and online news broadcasting. By leveraging social connections and group behaviours, group recommendation (GR) aims to provide more accurate and engaging content to a set of users rather than individuals. Recently, influence-aware GR has emerged as a promising direction, as it considers the impact of social influence on group decision-making. In earlier work, we proposed Influence-aware Group Recommendation (IGR) to solve this task. However, this task remains challenging due to three key factors: the large and ever-growing scale of social graphs, the inherently dynamic nature of influence propagation within user groups, and the high computational overhead of real-time group-item matching.
To tackle these issues, we propose an Enhanced Influence-aware Group Recommendation (EIGR) framework. First, we introduce a Graph Extraction-based Sampling (GES) strategy to minimise redundancy across multiple temporal social graphs and effectively capture the evolving dynamics of both groups and items. Second, we design a novel DYnamic Independent Cascade (DYIC) model to predict how influence propagates over time across social items and user groups. Finally, we develop a two-level hash-based User Group Index (UG-Index) to efficiently organise user groups and enable real-time recommendation generation. Extensive experiments on real-world datasets demonstrate that our proposed framework, EIGR, consistently outperforms state-of-the-art baselines in both effectiveness and efficiency.