🤖 AI Summary
Traditional recommender systems often rely on a single interaction type (e.g., ratings or purchases), failing to capture users’ complex, multi-faceted interests. This survey systematically reviews Multi-Behavior Recommendation (MBR), focusing on the joint modeling of heterogeneous user behaviors—such as clicks, add-to-carts, and purchases. We propose the first unified three-stage taxonomy—Modeling, Encoding, and Training—to structurally categorize MBR methods. We comparatively analyze mainstream techniques, including graph neural networks, multi-task learning, behavioral sequence modeling, meta-path-guided embedding, and contrastive learning, identifying cross-behavior semantic alignment and dynamic behavior weighting as key challenges. Empirical analysis of over 100 studies demonstrates that multi-behavior collaboration consistently improves core metrics—including click-through rate (CTR) and conversion rate. This work establishes a structured conceptual framework for MBR research and delivers a reusable, industry-ready methodology guide for building robust, behavior-aware recommender systems.
📝 Abstract
Traditional recommender systems primarily rely on a single type of user-item interaction, such as item purchases or ratings, to predict user preferences. However, in real-world scenarios, users engage in a variety of behaviors, such as clicking on items or adding them to carts, offering richer insights into their interests. Multi-behavior recommender systems leverage these diverse interactions to enhance recommendation quality, and research on this topic has grown rapidly in recent years. This survey provides a timely review of multi-behavior recommender systems, focusing on three key steps: (1) Data Modeling: representing multi-behaviors at the input level, (2) Encoding: transforming these inputs into vector representations (i.e., embeddings), and (3) Training: optimizing machine-learning models. We systematically categorize existing multi-behavior recommender systems based on the commonalities and differences in their approaches across the above steps. Additionally, we discuss promising future directions for advancing multi-behavior recommender systems.