12. One or more machine-readable storage medium storing instructions which, when executed by one or more processors, cause the performance of: extracting, by a question answering (QA) system, a set of features from a current question; performing, by the QA system, a comparison between (a) said set of features from said current question and (b) a set of features from one or more previously-submitted questions; selecting, based on the comparison, an answer to said current question from a set of answers to said one or more previously-submitted questions; displaying said answer in conjunction with a set of user-submitted answers to said current question; receiving user input that rates at least one user-submitted answer of said user-submitted answers higher than said answer; identifying one or more characteristics of the at least one user-submitted answer that are different from said answer; and based on the one or more characteristics, modifying one or more elements of the QA system.
12. One or more machine-readable storage medium storing instructions which, when executed by one or more processors, cause the performance of: extracting, by a question answering (QA) system, a set of features from a current question; performing, by the QA system, a comparison between (a) said set of features from said current question and (b) a set of features from one or more previously-submitted questions; selecting, based on the comparison, an answer to said current question from a set of answers to said one or more previously-submitted questions; displaying said answer in conjunction with a set of user-submitted answers to said current question; receiving user input that rates at least one user-submitted answer of said user-submitted answers higher than said answer; identifying one or more characteristics of the at least one user-submitted answer that are different from said answer; and based on the one or more characteristics, modifying one or more elements of the QA system. 22. The one or more machine-readable storage media of claim 12 , wherein: the one or more elements of the QA system include a plurality of QA experts, each of which is configured to select an answer to a given question; and modifying one or more elements of the QA system includes modifying information used by one or more of the plurality of QA experts to answer subsequent questions.