Concept Embedded Convolutional Semantic Model for Question Retrieval

Abstract

The question retrieval, which aims to find similar questions of a given question, is playing pivotal role in various question answering (QA) systems. This task is quite challenging mainly on three aspects: lexical gap, polysemy and word order. In this paper, we propose a unified framework to simultaneously handle these three problems. We use word combined with corresponding concept information to handle the polysemous problem. The concept embedding and word embedding are learned at the same time from both context-dependent and context-independent view. The lexical gap problem is handled since the semantic information has been encoded into the embedding. Then, we propose to use a high-level feature embedded convolutional semantic model to learn the question embedding by inputting the concept embedding and word embedding without manually labeling training data. The proposed framework nicely represent the hierarchical structures of word information and concept information in sentences with their layer-by-layer composition and pooling. Finally, the framework is trained in a weakly-supervised manner on question answer pairs, which can be directly obtained without manually labeling. Experiments on two real question answering datasets show that the proposed framework can significantly outperform the state-of-the-art solutions.