Session-based Recommendation with Graph Neural Networks
Shu WuYuyuan TangYanqiao ZhuLiang WangXing XieTieniu Tan
Proposes a session-based recommendation framework that models user click sequences as directed graphs and applies graph neural networks with an attention mechanism to capture complex item transitions and predict next-item interactions without requiring user profiles.
Modern online platforms frequently encounter anonymous users whose historical profiles and long-term preferences are entirely unavailable. In these scenarios, recommendation systems must rely solely on the limited sequence of clicks generated within an active browsing session. Conventional sequential models struggle in this context because they attempt to estimate explicit user profiles from minimal data and only evaluate simple transitions between consecutive items, neglecting complex, multi-step relationships across the entire session.
The article evaluates whether transforming individual browsing sessions into graph structures and applying graph neural networks can improve next-click prediction accuracy. The authors set out to demonstrate that this graph-based approach can better capture intricate item transitions while generating robust session representations without needing explicit user profiles.
To test this concept, the authors developed a model that converts click sequences into directed subgraphs, uses gated graph neural networks to learn item relationships, and applies an attention mechanism to combine immediate user interest with broader session intent. The framework was evaluated against leading conventional, sequential, and recurrent neural network baselines using two benchmark e-commerce transaction datasets, Yoochoose and Diginetica, encompassing millions of interaction clicks.
The analysis revealed three primary findings. First, the proposed graph neural network method consistently outperformed all baseline algorithms across both datasets, achieving top-20 precision of 70.57% to 71.36% on Yoochoose and 50.73% on Diginetica, while also improving recommendation ranking quality. Second, while prior state-of-the-art recurrent models suffered notable performance drops on longer sessions—falling by roughly 6 to 11 percentage points in precision—the proposed model maintained stable accuracy across both short and long browsing sequences. Third, ablation tests demonstrated that combining immediate last-click interest with an attention-weighted global session preference yielded superior results compared to using either factor in isolation or relying on simple averaging.
These findings indicate that shifting from linear sequence modeling to graph-based structures significantly enhances recommendation accuracy in anonymous environments. By capturing complex item transitions and filtering out noisy, drifting user clicks, platforms can deliver more relevant suggestions. For digital businesses, improved recommendation precision directly supports higher user engagement, better conversion rates, and reduced reliance on tracking personal user history.
Organizations operating e-commerce or content platforms with high shares of anonymous traffic should consider evaluating graph-based architectures within their recommendation pipelines. Implementation teams should adopt hybrid session embeddings that balance immediate user actions with overall session context. Because the source notes that short training steps prevent overfitting on brief sessions, engineering teams should tune training schedules accordingly.
Confidence in these findings is supported by consistent empirical gains across multiple real-world benchmark datasets and varied session lengths. However, decision-makers should note that the evaluation relied on historical e-commerce clickstream data where sessions were filtered to exclude single-click visits and rare items. Further testing in live operational environments and with auxiliary product metadata, such as item categories and descriptions, is recommended before full-scale deployment.
- Paper: Session-based Recommendations with Recurrent Neural Networks, Balázs Hidasi et al. (2016). Read this earlier GRU-based session recommender first to understand the sequential-model baseline that the source’s graph approach is designed to improve upon.
- Paper: Graph Neural Networks in Recommender Systems: A Survey, Shiwen Wu et al. (2020). This later survey places session-based graph recommendation within a broader taxonomy of GNN methods, extending the source’s focused approach into a wider research landscape.
