Interactive Cross-Language Question Answering: Searching Passages versus Searching Documents

iCLEF 2004 is the first comparative evaluation of interactive Cross-Language Question Answering systems. The UNED group has participated in this task comparing two strategies to help users in the answer finding task: the baseline system is just a standard document retrieval engine searching machine-translated versions of the documents; the contrastive system is identical, but searching passages which contain expressions of the appropriate answer type. Although the users prefer the passage system because searching is faster and simpler, it leads to slightly worse results, because the document context (which is not available in the passage retrieval system) turns out to be useful to verify the correctness of candidate answers; this makes an interesting difference with automatic Q&A systems. In addition, our experiment sets a strong baseline of 69% strict accuracy, showing that Cross-Language Question Answering can be efficiently accomplished by users without using dedicated Q&A technology.