Outline Extraction with Question-Specific Memory Cells

Abstract

Outline extraction has been widely applied in online consultation to help experts quickly understand individual cases. Given a specific case described as unstructured plain text, outline extraction aims to make a summary for this case by answering a set of questions, which in fact is a new type of machine reading comprehension task. Inspired by a recently popular memory network, we propose a novel question-specific memory cell network (QSMCN) to extract information related to multiple questions on-the-fly as it reads texts. QSMCN constructs a specific memory cell for each question, which is sequentially expanded in recurrent neural network style. Each cell contains three specific vectors to first identify whether current input is related to corresponding question and then update question-specific case representation. We add a penalization term in the loss function to make extracted knowledge more reasonable and interpretable. To support this study, we construct a new outline extraction corpus, InjuryCase, 1 which is composed of 3,995 real Chinese occupational injury cases. Experimental results show that our method makes a significant improvement. We further apply the proposed framework on two multi-aspect extraction tasks and find that the proposed model also remarkably outperforms existing state-of-the-art methods of the aspect extraction task.