1. A method comprising: inputting key data to a finite state-based representation, wherein the key data is extracted from a dialog call detail record associated with a run-time behavior of a dialog between a spoken dialog service and a user, wherein the dialog call detail record traces and records turns in the dialog during a call by the user; and determining, via a processor, whether the finite state-based representation has accepted the key data based on whether the finite-based representation accepts a sentence from the dialog in a grammar, the grammar defined by a Backus-Naur Form implemented as the finite state-based representation.