Clippers 10/25: Lingbo Mo on Controllable Decontextualization

Yes/No or polar questions represent one of the main linguistic question categories. They consist of a main interrogative clause, for which the answer is binary (assertion or negation). Polar questions and answers (PQA) represent a valuable knowledge resource, present in many communities and other curated QA sources, such as forums or e-commerce applications. Using answers to polar questions alone in other contexts is not trivial. Answers are contextualized, and presume that the interrogative question clause and any shared knowledge between the asker and answerer are provided. We address the problem of controllable rewriting of answers to polar questions into decontextualized and succinct factual statements. We propose a Transformer sequence-to-sequence model that utilizes soft constraints to ensure controllable rewriting, such that the output statement is semantically equivalent to its PQA input. We conduct the evaluation on three separate PQA datasets as measured through both automated and human evaluation metrics and show the effectiveness of our proposed approach compared with existing baselines.