In nearly every aikido dojo, the focus is on learning technique, and the purpose of this is to ingrain appropriate body movements, to teach awareness, to develop sensitivity and to give us a means of learning the fundamental principles that are hardwired into our art. However, many teachers never look beyond the mechanics of the movement and all to often the message that this sends to students is that they have to do something to their partner, as opposed to learn to work with their partner. Success may be measured by the fact that the partner has been thrown, and little attention paid to how the partner felt about the throw. Was it achieved because you were stronger than them, or faster than them or simply because your grasp of the mechanics of the body made it easy to use their wrist as an appropriate lever to throw them. If there is no attempt to receive the attack fully, to blend with it and deal with it harmoniously, then its not aikido, it's just effective martial art technique.
Of course, that begs the question, how do we measure effectiveness? On a surface level, success is all to often the measure is seen to be your ability to be the one left standing when someone attacks you. But let's go a little deeper and question whether the fact that you have dealt with the attack on a surface level is really a decent measure of success. Let's just pretend, that I train with you for the first time and you use one of the wrist techniques to throw me, such as nikkyo, sankyo, or kotagaeshi, and in doing so you damage my wrist. The likelihood is that you left me feeling angry or fearful. In the first case, you may have won the battle, but now you may well have started a war. In the second, I'm not going to trust you with my body again and you have lost a training partner.
If you are the teacher and I am the student, I'm not coming back to your club unless I happen to have masochistic tendencies, and sadly there are plenty of students who believe that if its not painful then they haven't learnt anything useful. What a reflection on our society!
In short, aikido should not be deemed effective just because you have successfully completed a technique, it is only effective and its only aikido when you are able to truly receive an attack, and create a result where both parties walk away feeling good about it.
It all comes down to this, we simply have to understand the purpose of our training and when we are clear about that, then through technique we can develop qualities that ultimately allow us to throw technique away. In reality, every situation is unique and when someone attacks, you have no time to plan a response, but through good training you should move in an appropriate way and receive the technique with the right state of mind. Then you are able to re-direct the attack in a positive way. You probably won't even know what you did until it is done and even then you might not recognise it as a technique. However, it is certain that done correctly, you will have employed all the skills and qualities that can be learnt through the exploration of good technique. In the end, technique becomes unimportant, but employing good principles is fundamental. The good news is that you may only have a few hours each week to practice your technique, but you have a lifetime to practice good principles.