[Jack000]

I think the main problem with voice interfaces is that it's not discoverable. You need a good understanding of what the system can and cannot do, its current state etc before even speaking.

CLI has the same issue, but at least you can man-xxx, which I imagine works a lot better in text than it does in audio.

[criddell]

I think the goal is that the system gets to be good enough that nobody worries about discoverability any more.

I think Google is quickly getting there with their search interface. I'm always amazed at what a good job Google does when I ask it a question like "what's the name of the instrument powered by steam" and milliseconds later it's showing me info about calliopes.