Abstract: A method and apparatus are used for analyzing dialogs in an interactive natural language speech recognition system. As a telephone call is received in the interactive natural language speech recognition system, user utterances are digitized and stored. A data log is formed which stores the prompt played, the dialog state, the address location of the audio recording of the user's responses, the recognition grammar, the recognition result type, the recognized word string, the understood meaning/interpretation, and the recognition latency. The telephone call can be virtually reconstructed from the stored user utterances and the data log. An automatic data analysis tool provides information regarding the relative success and failure of the various dialogs as an aid to modifying the dialogs to improve system performance.