13. A computer-implemented method comprising: receiving a first search query during a search session, the first query comprising first search terms, wherein each of the first search terms has a respective first ordinal position, each first ordinal position of each first search term defines a position of the first search term in the first search query relative to other first search terms in the first search query; receiving a subsequent search query during the search session after receipt of the first search query, the subsequent search query being another search query and being separately received from the first search query, the subsequent search query comprising subsequent search terms including a second term, the second term being different from each of the first search terms, wherein each of the subsequent search terms has a respective second ordinal position, each second ordinal position of each subsequent search term defines a position of the subsequent search term in the subsequent search query relative to other subsequent search terms in the subsequent search query; determining common terms between the first search query and the subsequent search query based on a comparison of the first ordinal positions to the second ordinal positions and the first search terms and the subsequent search terms, wherein each of the common terms is a search term that is included in the first search terms and in the subsequent search terms and has a first ordinal position in the first search query equal to a second ordinal position in the subsequent search query; identifying adjacent common terms, the adjacent common terms being common terms that are located adjacent to one another in the first search query and adjacent to one another in the subsequent search query; and submitting one or more pairs of adjacent terms in the subsequent query to a bigram analysis to identify bigrams in the subsequent search query, wherein any pair of terms in the subsequent query that includes the second term and any of the terms of the first search query is not submitted to the bigram analysis.
14. The computer-implemented method of claim 13 , wherein the first search query includes a particular first search term immediately followed by a another first search term that is different from the particular first search term and the another first search term is different from the second term; the subsequent search query includes the another first search term immediately followed by the particular first search term; and any pair of terms in the subsequent search query that includes either the particular first search term or the another first search term is not submitted to the bigram analysis.