18. A system, comprising: one or more processors; and memory, communicatively coupled to the one or more processors, storing one or more modules configured to: electronically receive a natural language input phrase from an interface device; attribute a concept to the natural language input phrase, wherein the concept is a breakdown of one or more ideas in the input phrase and the attributing is based at least in part on a pattern among terms in the natural language input phrase; associate a word in the natural language input phrase with the concept; search a database of a set of documents to identify one or more documents associated with the attributed concept to be included in a response to the natural language input phrase; maintain the concept during an interactive session between the natural language processor and the interface device; receive an ambiguous natural language input phrase during the interactive session; and determine that the ambiguous natural language input phrase has a same meaning as the word that is associated with the concept.
25. The system of claim 18 , wherein the one or more modules are further configured to search the set of documents in the database to identify one or more documents containing at least one term found in the natural language input phrase.