Roger McNamee uses some interesting terms in a discussion of service automation. He differentiates "half-duplex" automation from "full-duplex" automation:

I think there's more than one thread here: half-duplex automation, which is what you have on Google or eBay (where it will give you information automatically if you give it some kind of interaction), and full-duplex [automation], which is what you have [with] TiVo and in a very small number of cases where you can set up automation ahead of time. To me, that's the thread that hasn't really started yet: I see enormous potential on the systems in place at the other end being able to automatically service stuff for you.

From Has the Internet Been Underhyped? :: AO
Referenced Wed Jan 05 2005 08:53:42 GMT-0700

The problem with full-duplex automation is that its hard to specify what you want precisely enough that the agent can carry out your wishes. Tivo's a special case since its all time based and there's a precise schedule. Build a GUI and you're done. Automating service from Amazon, for example, is harder.