IVR or All Voice Design?
When we started this project, we had to determine our focus. Are we limiting ourselves to IVR? Or are we going to include multi-modal design? Or anything that uses a voice interface? The conclusion we reached was that we had to start somewhere, be comfortable with that, and then possibly expand. So the decision was made to focus on IVR.
Does that mean what is here doesn't apply to an app on a phone with voice control or a car navigation system? Absolutely not. There will be places where the use case does indeed change some recommendations, but a lot of them stay the same, especially for conversational (as opposed to command-and-control) designs. A lot of them are core to voice regardless of the application.
We look forward to future iterations of this project where we can expand into non-IVR realms, and welcome input from those who have done it.