Evaluation of the Clinical Question Answering Presentation

Question answering is different from information retrieval in that it attempts to answer questions by providing summaries from numerous retrieved documents rather than by simply providing a list of documents that requires users to do additional work. However, the quality of answers that question answering provides has not been investigated extensively, and the practical approach to presenting question answers still needs more study. In addition to factoid answering using phrases or entities, most question answering systems use a sentence-based approach for generating answers. However, many sentences are often only meaningful or understandable in their context, and a passage-based presentation can often provide richer, more coherent context. However, passage-based presentations may introduce additional noise that places greater burden on users. In this study, we performed a quantitative evaluation on the two kinds of presentation produced by our online clinical question answering system, AskHERMES (http://www.AskHERMES.org). The overall finding is that, although irrelevant context can hurt the quality of an answer, the passage-based approach is generally more effective in that it provides richer context and matching across sentences.