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 a person in the question, wherein the cohorts are persons meeting a threshold of similar attributes to the person of the question and available in a corpus of data to answer the question; extracting answers and evidence from data of the cohorts; combining and ranking the extracted answers and evidence from the cohorts; using the combined and ranked answers and evidence to gather statistically significant evidence; and answering the question with the gathered statistically significant evidence.