Self-Supervised Reinforcement Learning with dual-reward for knowledge-aware recommendation

To improve the recommendation accuracy and offer explanations for recommendations, Reinforcement Learning (RL) has been applied to path reasoning over knowledge graphs. However, in recommendation tasks, most existing RL methods learn the path-finding policy using only a short-term or single reward, leading to a local optimum and losing some potential paths. To address these issues, we propose a Self-Supervised Reinforcement Learning (SSRL) framework combined with dual-reward for knowledge -aware recommendation reasoning over knowledge graphs. Then, we improve Actor-Critic algorithm by using a dual-reward driven strategy, which combines short-term reward with long-term incremental evaluation. The improved algorithm helps the policy guide path reasoning in an overall situation. In addition, to find the most potential paths, in the improved Actor-Critic algorithm, a loss constraint of each sample is used as a reinforced signal to update the gradients. With some improvements against baselines, experimental results demonstrate the effectiveness of our framework.(c) 2022 Elsevier B.V. All rights reserved.