Lexical validation of answers in question answering

International audienceQuestion answering (QA) aims at retrieving precise information from a large collection of documents, typically the Web. Different techniques can be used to find relevant information, and to compare these techniques, it is important to evaluate question answering systems. The objective of an Answer Validation task is to estimate the correctness of an answer returned by a QA system for a question, according to the text snippet given to support it. We participated in such a task in 2006. In this article, we present our strategy for deciding if the snippets justify the answers. We used a strategy based on our own question answering system, and compared the answers it returned with the answer to judge. We discuss our results, and show the possible extensions of our strategy. Then we point out the difficulties of this task, by examining different examples