Title: Hierarchical Variational Attention for Sequential Recommendation
Authors: Jing Zhao, Pengpeng Zhao, Yanchi Liu, Victor Sheng, Zhixu Li and Lei Zhao
Abstract: Attention mechanisms have been successfully applied in many fields, including sequential recommendation. Existing recommendation methods often use the deterministic attention network to consider latent user preferences as fixed points in low-dimensional spaces. However, the fixed-point representation is not sufficient to characterize the uncertainty of user preferences that prevails in recommender systems. In this paper, we propose a new Hierarchical Variational Attention Model (HVAM), which employs variational inference to model the uncertainty in sequential recommendation. Specifically, the attention vector is represented as density by imposing a Gaussian distribution rather than a fixed point in the latent feature space. The variance of the attention vector measures the uncertainty associated with the user's preference representation. Furthermore, the user's long-term and short-term preferences are captured through a hierarchical variational attention network. Finally, we evaluate the proposed model HVAM using two public real-world datasets. The experimental results demonstrate the superior performance of our model comparing to the state-of-the-art methods for sequential recommendation.
