More complex applications need to track state, so that actions are interpreted in the proper context.

1. Different user inputs may have different consequences depending on state.
2. Speech input may allow more efficient expression of user goals, which are best implemented through direct access to the functional level of the application as opposed to the emulation of an existing interface.

   Tracking state is essential in cases where the user has alternate means of changing application state (for example, input through a non-speech mode).