1. A method for analyzing cohorts to answer a question in a question answering system, the method comprising the steps of: identifying the cohorts for an entity in the question, wherein the cohorts are entities with similar characteristics to an entity of the question and available in a corpus of data to answer a question; extracting answers and evidence from the cohorts; combining and ranking the extracted data; using the combined and ranked data to gather statistically significant evidence; and answering the question with the gathered evidence.