3. The system of claim 1 , wherein said plurality of grammars are determined based on a website, and wherein the set of computer executable instructions are further operable to configure the computer to achieve the goal during the interaction with the user without requiring the interaction to follow the structure of the website.
1. A system comprising: a) an input connection, wherein said input connection is operable to receive a natural language input from a user; b) a computer readable medium, said computer readable medium having stored thereon a plurality of grammars, wherein said plurality of grammars is organized according to a hierarchy comprising five levels, wherein: i) a grammar from the lowest of the five levels comprises a vocabulary comprising words corresponding to natural language statements; and ii) for each level above the lowest level in the hierarchy, each grammar from that level comprises one or more elements provided by a grammar from the next lower level in the hierarchy; c) a computer, said computer configured with a set of computer executable instructions operable to, during an interaction with the user, cause the computer to perform a set of acts comprising: i) based on the natural language input from the user, determine a goal for the user; ii) determine a set of information necessary for the user to provide for the goal to be completed, wherein determining the set of information is performed using a first grammar from said plurality of grammars; iii) determine a set of missing information from the set of information, wherein the set of missing information comprises information which has not been provided by the user during the interaction; iv) based on a second grammar from the plurality of grammars, determine a prompt to provide to said user to obtain one or more elements from said set of missing information; and v) provide said prompt to said user.