Generating Explanations for Recommendation Systems via Injective VAE

Abstract

Generating explanations for recommendation systems is essential for improving its transparency since informative explanations such as generated reviews can help users comprehend the reason for receiving a specified recommendation. The generated reviews should be specific for the given user, item, and rating, however, recent works only focus on designing more and more powerful decoder, merely treating this task as a plain natural language generation process. We argue that there may exist the risk that the powerful decoder neglects the input embeddings and suffers from the biases that exist in data. In this paper, we propose a novel Injective Variational Autoencoders (InVAE) for generating high-quality reviews. Specifically, we employ a Collaborative Kullback-Leibler divergences (CKL) mechanism to building a better latent space that captures meaningful information. Base on this, the Spectral Regularization on Flow-based transformation (SRF) method is designed to backward transfer the priorities of generated latent variables to the input embeddings. Therefore, our method can construct more informative input embeddings and provides more specific explanations for different inputs. Extensive empirical experiments demonstrate that our model can construct much more meaningful feature embeddings and generate personalized reviews in high quality.