1. A computer-implemented ranking method comprising: performing a search on a database according to search criteria; receiving, from the database over a network, a document resulting from the search, the document containing terms that match the search criteria; calculating a standard deviation of a probability distribution function representing a distribution of the terms in the document that match the search criteria; determining relative distances between the terms in the document that match the search criteria according to the standard deviation; calculating a proximity boost value using the relative distances; applying the proximity boost to a base relevancy score of the document to determine a relevancy ranking for the document; and ranking the document according to the relevancy ranking.