Architecture for generating responses to search engine queries. Question/answer pairs are used to provide a predefined question hierarchy to facilitate a search. Informative terms and one or more questions are associated with each question node of the hierarchy. A question posed is mapped into the hierarchy to the most similar question class node, as determined by passages of the question and/or comparing the informative terms of the question and the question/answer node. Weighted informative terms associated with that node are then returned, and can be used by an automatic question answering system to more effectively find an answer to a question.