[jfaucett]

> as an intentional deficiency is an interesting design decision.

well, in semantics/pragmatics these discourse particles are often not deficiencies at all. They are signals with practical semantic purpose. "hmms" and "uhs" can signal attentiveness, turn-taking (turn holding, turn yielding, etc), agreement - just to name a few.

For any machine system to be able to pass as human, it will have to be able to control these nuances or people will pick up on something being wrong, though they might not be able to articulate precisely what.

[ghayes]

I really enjoyed the machine's "uhs" and "uhms" in the demo speech. However, I felt the "uh-huh"s sounded forced. It's funny how these subtleties are very important in human conversation.

[2bitencryption]

I think probably because "uh-huh" can have many different meanings based on inflection!

As a "non-word", it relies heavily on how it is conveyed.

Imagine someone asks you a question, I bet you can answer using just the word "uh-huh" but conveying these different emotions:

rude, perky, bored, upset, annoyed, dubious, excited

and probably a dozen more.

Even using the "perky" or "happy" one in a situation where it isn't warranted might sound rude or unthoughtful!