Deriving disambiguous queries in a spoken interactive ODQA system

Recently, open-domain question answering (ODQA) systems that extract an exact answer from large text corpora based on text input are intensively being investigated. However, the information in the first question input by a user is not usually enough to yield the desired answer. Interactions for collecting additional information to accomplish QA is needed. This paper proposes an interactive approach for spoken interactive ODQA systems. When the reliabilities for answer hypotheses obtained by an ODQA system are low, the system automatically derives disambiguous queries (DQ) that draw out additional information. The additional information based on the DQ should contribute to distinguishing effectively an exact answer and to supplementing a lack of information by recognition errors. In our spoken interactive ODQA system, SPIQA, spoken questions are recognized by an ASR system, and DQ are automatically generated to disambiguate the transcribed questions. We confirmed the appropriateness of the derived DQ by comparing them with manually prepared ones.