1. An evidence evaluation method based on question answering, comprising: converting information into a collection of questions by a processor; determining answers to the collection of questions; marking a fact in the information as being supported if one or more of the answers to the collection of questions support the fact; marking a fact in the information as being refuted if one or more of the answers to the collection of questions refute the fact; collecting evidence that support the answers; and adding the evidence to a model of information to create an updated model of information.