Re: Talk or not to talk?
I'd like to argue that for real comprehension of techniques, both talk and show is necessary.
I teach adults in tertiary education and 6 months ago I came back to aikido after a 7 year break. I have seen students in both situations completely confounded by only one method of teaching.
Just talking often doesn't articulate the 'feel' of a technique. But it can guide you where to move so you can feel it. Or indicate the moment something should/can happen. Respectively, straight demonstration only can leave a rank amatuer at a total loss. A student learning shiho nage can see the position of nage's shoulder in the throw and think that's how it works when really it's got nothing to do with it. Without sempai saying "hey, don't push your shoulder into uke's armpit" a bad habit will be reinforced.
I guess what I'm trying to say is that some things can't be verbalised and have to be felt, but somethings can't be seen or if they're felt they're not comprehended as 'the moment' of capturing uke's centre if there's no verbal communication to highlight it.