1. A method for improving the accuracy by which a database of search queries represent human search behavior, the method comprising: determining, by a computer, an expected quantity of search queries; comparing a quantity of the search queries to the expected quantity of search queries; determining that the quantity of search queries exceeds the expected quantity of search queries by at least a predetermined margin; selecting a number of search queries of the quantity in accordance with an amount by which the quantity exceeds the expected quantity; and removing the selected number of search queries from the quantity, where the search query includes a search term and a source, where the determining the expected quantity of search queries includes determining an expected quantity of search queries based on a proportion of search volume attributable to the search term relative to the source, where the expected quantity of search queries based on a proportion of search volume attributable to the search term relative to the source is determined for a particular geographic region.