Surveys are scientific investigations based upon populations that are designed to estimate the prevalence of a particular characteristic in a geographical area. Surveys are probably most familiar to the reader as the polling surveys that are used to estimate the percentage of an electorate in favor of one candidate or another for upcoming elections. However, the exact same methodology can be used to identify a particular physiologic burden or exposure in the population which might lead to a particular disease. In other instances, less scientific studies are used to estimate the occurrence of adverse events for a specified user population. Surveys are frequently of value to a pharmaceutical company to identify the number of individuals who would potentially be in need of a genetic marker test or treatment of interest.