A cohort analysis mechanism analyzes cohorts with similar attributes to extrapolate additional knowledge and answer a question in a question answering system. The cohort analysis mechanism identifies cohorts for an entity of the question and extracts relevant data concerning the cohorts. The cohort analysis mechanism aggregates the relevant information for evidence scoring and answer scoring to answer a question posed to the question answering system. The aggregating of the data includes combining and ranking answers from the cohorts, gathering evidence and then answering the question with the gathered evidence.
Please help me write a proper abstract based on the patent claims. CLAIM: 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. 2. The method of claim 1 wherein the cohort analysis mechanism is part of a question answering application that answers a natural language question. 3. The method of claim 1 wherein the question is a medical question for a patient and the cohort analysis mechanism processes the medical history of the patient and finds the cohorts from medical histories of other patients to predict an answer from the cohorts. 4. The method of claim 1 wherein the cohort analysis mechanism determines an answer to the question using evidence gathered from a set of cohorts where case attributes in the set of cohorts does not match exactly attributes of the question. 5. The method of claim 4 wherein the question is a medical question for a patient and the cohort analysis mechanism processes the medical history of the patient and finds the cohorts from medical histories of other patients to predict an answer from the cohorts. 6. The method of claim 5 wherein the cohort analysis mechanism combines the answer from the cohorts with answers using conventional question answering in an answer scoring block of a conventional question answering system to answer the question. 7. A method for analyzing cohorts to answer a question in a question answering system, the method comprising the steps of: providing a cohort analysis mechanism that executes on at least one processor that analyzes cohorts with similar attributes, wherein the cohorts are entities with similar characteristics to an entity of the question and available in a corpus of data, wherein the cohort analysis mechanism is part of a question answering application that answers a natural language question; analyzing the cohorts to answer a question comprising: identifying the cohorts for an entity in the question; extracting answers and evidence from the cohorts; combining and ranking the extracted data; using the combined and ranted data to gather statistically significant evidence; answering the question with the gathered evidence; wherein the cohort analysis mechanism determines an answer to the question using evidence gathered from a set of cohorts where case attributes in the set of cohorts does not exactly match attributes of the question; wherein the question is a medical question for a patient and the cohort analysis mechanism processes the medical history of the patient and finds the cohorts from medical histories of other patients to predict an answer from the cohorts; and wherein the cohort analysis mechanism combines the answer from the cohorts with answers using conventional question answering in an answer scoring block of a conventional question answering system to answer the question.