Originally posted by ca
As for 'mat-teaching' i.e., telling your partner what to do: I really dislike this. I think it robs the kohai of the chance to learn on their own. I'm not even a fan of the 'resist to teach them' method as sometimes size makes it hard for someone to resist even bad technique, some beginners just throw in more muscle--which can be dangerous to resist, especially if uke is small, and --gasp--sometimes sempai are actually WRONG in what they are trying to show and force the correct kohai to abandon the correct technique out of fear of hurting the resisting uke. I think is is just best to give a sincere, committed attack appropriate for nage to do the shown technique, at a speed appropriate to nage's level. As they go through the motions they will either get it right, or should see that you and they are not looking like what was just shown. At that point, if they are asking what they did wrong, they can be encouraged to try something different from what they did last. I think the exploring of the technique--including the wrong turns and dead ends, are important to growth. If you want to teach them, then do the technique correctly, clearly, crisply, even very very slowly if you need to---they should learn from what you are doing, not what you are saying. In my opinion.
I agree completely. Our Sensei occasionally reminds us of two things, which I will try to paraphrase here to the best of my understanding.
There is one sensei on the mat. Students should not teach other students during class. It might be okay for very senior students to offer an occasional correction, but even that should be minimized. The reasoning is simple: most students do not have the necessary skill and perception to be critiquing someone else's technique yet. Sensei keeps a close eye on everyone (our dojo is small) and if he is dissatisfied with your progress in some way, he will address it as he sees fit.
It is uke's job to be sincere and to respond naturally to nage. It is not uke's job to try to figure out what nage is going to do and try to prevent it, or to try to guide uke one way or the other, except by responding naturally and sincerely. If that response means that the technique doesn't turn out as nage expected, that's fine. That's good feedback for nage. To do anything else is to prevent uke's practice of ukemi, which is the door to understanding Aikido.
On this latter point, I have sometimes had a senior student "jam" me, and then offer instruction. Even though I generally did learn something from it, I do see Sensei's point; if possible, the student should always figure it out for him/herself. That way, the student learns it more thoroughly and intimately than if it's simply told and the student gets enough of a superficial understanding to make the movement work in that particular case.