1. A method comprising: accessing a record stored in one or more tangible media, the record recording a plurality of clusters of a plurality of documents, a document comprising a plurality of words, a cluster comprising a plurality of satisfactorily affine words of the plurality of words, a cluster indicating a theme; establishing a number of themes of each document of at least a subset of the plurality of documents; determining a specificity of the each document according to the number of themes by: determining that the each document is more specific if the each document has a lower number of themes; and determining that the each document is less specific if the each document has a higher number of themes; receiving a search query comprising a document specificity request, the document specificity indicated using a slider; and retrieving one or more documents of the plurality of documents that satisfy the search query and the document specificity request.