'Following' is not a term I see discussed much on the forums and it is a term which I have been used to hearing and using since the day I started aikido. Uke's ability to 'follow' nage's technique for me, is where I have made some of my greatest insights into what and how the technique is supposed to go.
Now, when this is done correctly, and what I mean by correctly is, uke is giving a sincere attack, whilst at the same time 'not' giving away his centre, is completely on balance, and is sensitive enough to be able to feel every move and change of direction that nage makes. So if nage performs the technique correctly, and what I mean by correctly is, they are leading nage's intent/ki and not trying to use muscle to make it work, it will feel effortless.
When any of the principles of aikido are not in place, (using muscular strength, no centre, bad posture, etc), uke 'stops' the technique, because, basically it's virtually impossible to 'throw' a fully co-ordinated body that is on balance/centred. When all is working, it feels like a completely 'collusive' encounter, when it is not, it feels like you are trying to throw a tree.
My own teacher has spent a lifetime espousing non-resistant following, as it trains the sort of sensitivity and strength that he is trying to teach.
I spend a great deal of time focussing on the art of following, as a teacher it gives me the information I need if I can't see the problem a student is having, I can feel where they are going wrong as I have followed the technique to the point of failure, et voila, I can give them the point of resolution.
What terms do you use to describe this practice (if you do)?