7. At least one computer-readable storage medium storing computer-executable instructions that, when executed, perform a method comprising: receiving, from a user, a text input expressing a question asking for recommendation of a product having a requested characteristic; generating, in response to the question, an answer that identifies a product having the requested characteristic for recommendation to the user; analyzing, using natural language analysis, a plurality of product reviews comprising natural language text evaluations of the product, including analyzing the natural language in at least one passage of text in at least one product review of the plurality of product reviews to determine whether the natural language in the at least one passage of text has a meaning indicating that the product has the requested characteristic, at least in part by converting the question to one or more hypotheses and determining whether the natural language in the at least one passage of text has a meaning that entails at least one of the one or more hypotheses; in response to determining via the natural language analysis that the natural language in the at least one passage of text has a meaning indicating that the product has the requested characteristic, identifying the at least one passage of text in the at least one product review as providing supporting evidence for the product in answer to the question; and presenting to the user, in response to the text input, the answer and the at least one passage in the at least one product review identified as providing supporting evidence for the answer.
7. At least one computer-readable storage medium storing computer-executable instructions that, when executed, perform a method comprising: receiving, from a user, a text input expressing a question asking for recommendation of a product having a requested characteristic; generating, in response to the question, an answer that identifies a product having the requested characteristic for recommendation to the user; analyzing, using natural language analysis, a plurality of product reviews comprising natural language text evaluations of the product, including analyzing the natural language in at least one passage of text in at least one product review of the plurality of product reviews to determine whether the natural language in the at least one passage of text has a meaning indicating that the product has the requested characteristic, at least in part by converting the question to one or more hypotheses and determining whether the natural language in the at least one passage of text has a meaning that entails at least one of the one or more hypotheses; in response to determining via the natural language analysis that the natural language in the at least one passage of text has a meaning indicating that the product has the requested characteristic, identifying the at least one passage of text in the at least one product review as providing supporting evidence for the product in answer to the question; and presenting to the user, in response to the text input, the answer and the at least one passage in the at least one product review identified as providing supporting evidence for the answer. 8. The at least one computer-readable storage medium of claim 7 , wherein the at least one product review comprises an evaluation of the product made by a purchaser of the product.