Interactive natural language question answering over knowledge graphs.

As many real-world data are constructed into knowledge graphs, providing effective and convenient query techniques for end users is an urgent and important task. Although structured query languages, such as SPARQL, offer a powerful expression ability to query RDF datasets, they are difficult to use. Keywords are simple but have a very limited expression ability. Natural language question (NLQ) is promising for querying knowledge graphs. A huge challenge is how to understand the question clearly so as to translate the unstructured question into a structured query. In this paper, we present a data + oracle approach to answer NLQs over knowledge graphs. We let users verify the ambiguities during the query understanding. To reduce the interaction cost, we formalize an interaction problem and design an efficient strategy to solve the problem. We also propose a query prefetching technique by exploiting the latency in the interactions with users. Moreover, we devise a hybrid approach that incorporates NLP-based, data-driven, and interaction techniques together to complete the question understanding. Extensive experiments over real datasets demonstrate that our proposed approach is effective as it outperforms state-of-the-art methods significantly.