1. An apparatus comprising: at least one processor; a memory coupled to the at least one processor; a cohort analysis mechanism residing in the memory and executed by the at least one processor that analyzes cohorts with similar attributes to answer a question input to the cohort analysis mechanism by aggregating data from the cohorts to gather statistically significant evidence to answer the question, and wherein the cohorts are entities with similar characteristics to an entity of the question and available in a corpus of data.