18. The apparatus of claim 15 , further comprising: performing a search on the database according to a second search criteria; calculating a second proximity boost value for the second search criteria; and combining the proximity boost value for the search criteria and the second proximity boost value for the second search criteria to calculate a cumulative proximity boost value.
15. An apparatus comprising: a memory device storing instructions for determining relevant search results; and a processor executing the instructions to perform the steps of: 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 value 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.