Looks like I originally posted this overview a little before it was truly ready for public release. After I thought about it some more I decided that it makes more sense to add another level differentiating between level 2, which is a hybrid level incorporating a compliant attack followed by passive resistance, and pure passive resistance, now at level 3, which I think does have some usefulness as a transitional level between semi-compliant and active resistance. Since Jun Akiyama would not allow me to edit the original post, here is the new list:
- Compliant: Uke works to establish and maintain passive connection with nage's center. If nage breaks the connection, uke will reestablish it by "following" the nage's movement. This level of training is what is typically found in aikido and it is only useful for learning and practicing choreographed movements.
- Semi-Compliant: Uke initially establishes passive connection with nage's center via his attack, but does not attempt to reestablish it if nage breaks it. Uke also does not attempt to break the connection himself but allows nage to control and throw him as long as nage maintains the connection. This is a hybrid level with the initial attack being compliant and the remainder of the ukemi being done at the level of passive resistance, and it is useful for training nage how to maintain a connection with uke's center.
- Passive Resistance: Uke initially does not establish any connection with nage's center via his attack but also does not try to break connection once nage establishes it, instead allowing nage to throw him as in the previous level as long as the connection is maintained. This is a transitional level between semi-compliant and active resistance, and it is useful for training nage how to initially establish connection with uke”Ēs center.
- Active Resistance: As in the previous level, uke initially does not establish any connection with nage's center via his attack, however following this uke attempts to break any connection that nage attempts to establish with his center and thus prevent nage from throwing him. This is useful for training nage how to spontaneously and continuously reestablish connection with uke's center and also excellent training for uke to learn how to avoid being thrown.
- Countering: Uke attempts to establish an active connection with nage's center via his attack with the intention of physically moving nage's body (typically to the floor). Uke also works to reestablish this connection if nage breaks it and to thwart or break free from any of nage”Ēs attempts to establish such a connection with uke”Ēs center. This is freestyle kaeshi-waza practice with no distinction between the roles of uke and nage.
The intent of this list is to show how the levels of semi-complaint, passive resistance, and active resistance can be used to gradually increase the challenge that uke presents to nage as nage progressively learns the building blocks of controlling uke's center. They are training methods meant to work towards the point where nage can immediately take control of uke's center and then maintain that control through a technique despite uke's attempts to break that control and either to relaunch another attack or counter nage's technique.
Ultimately all a list like this does is to try to describe a complex real-life interaction in way that makes it easy to isolate and understand some aspects of the interaction. The options that Andrew proposed are another way of looking at resistance training, focusing on a slightly different aspect of the interaction. Both approaches are useful in describing some of the concepts to think about in engaging in this kind of training, although both are also limited in that they look only at some small aspect of a scenario that can, in practice, be very rich and complex. However, this is also true of all other approaches to training martial arts as well.