Question answering in knowledge bases: A verification assisted model with iterative training

Question answering over knowledge bases aims to take full advantage of the information in knowledge bases with the ultimate purpose of returning answers to questions. To access the substantial knowledge within the KB, many model architectures are hindered by the bottleneck of accurately predicting relations that connect subject entities in questions to object entities in the knowledge base. To break the bottleneck, this article presents a novel model architecture, APVA, which includes a verification mechanism to check the correctness of predicted relations. Specifically, APVA takes advantage of KB-based information to improve relation prediction but verifies the correctness of the predicted relation by means of simple negative sampling in a logistic regression framework. The APVA architecture offers a natural way to integrate an iterative training procedure, which we call turbo training. Accordingly, we introduce APVA-TURBO to perform question answering over knowledge bases. We demonstrate extensive experiments to show that APVA-TURBO outperforms existing approaches on question answering.