11. A system comprising: one or more processors; a memory storing instructions that, when executed by the one or more processors, cause the system to: host a social network comprising a plurality of communities associated with a plurality of users; identify, from the plurality of communities, a set of communities that a first user belongs to; determine a list of classifications for the first user based upon the set of communities; determine a degree of personalization based on an amount that the first user has participated in each community of the set of communities; determine personalization information from the list of classifications associated with the first user and the degree of personalization; generate a personalized search query based upon the personalization information; and search a content index using the personalized search query to produce a search result set comprising documents relevant to the personalized search query.
11. A system comprising: one or more processors; a memory storing instructions that, when executed by the one or more processors, cause the system to: host a social network comprising a plurality of communities associated with a plurality of users; identify, from the plurality of communities, a set of communities that a first user belongs to; determine a list of classifications for the first user based upon the set of communities; determine a degree of personalization based on an amount that the first user has participated in each community of the set of communities; determine personalization information from the list of classifications associated with the first user and the degree of personalization; generate a personalized search query based upon the personalization information; and search a content index using the personalized search query to produce a search result set comprising documents relevant to the personalized search query. 12. The system of claim 11 , wherein determining the personalization information further comprises receiving a suggested search term from a member of the set of communities, wherein the personalized search query, generated based upon the personalization information, includes the suggested search term, and wherein searching the content index to produce the search result set is based upon the personalized search query including the suggested search term.