First let Sifu Lars Böckers say his piece:

There are many ways of wasting valuable training time, but one of the most effective and subtle is to preoccupy your partner and yourself with constant corrections in the belief that you are working particularly constructively. Occasionally I like to overlook all the technical details and mistakes, merely watching how the training partners treat each other during a class. What I find is constant correction, know-it-alls and discussions. Often some incorrect or ill-founded criticism will make my hair stand on end, and even if the know-all (in the positive sense of the word) is actually right, correcting a partner is often unproductive and makes the training ineffective. At the very least it is depriving him of valuable experience.
One problem is that the student who knows things better unfortunately and all-too-often does not, but only thinks he is someone who knows better. This often results in creative and spectacular, but unfortunately wrong techniques. And if the partner also thinks he knows better in some way, the whole thing escalates to the extent that when I am walking round, I no longer recognise the exercise I gave them to do. It is even worse, however, if the know-all has such natural conviction and authority that his poor training partner accepts and follows the wrong corrections.
Moreover, it is all the more embarrassing if the know-all does not realise that while he thinks he KNOWS better, he is unable to DO better and makes the same mistakes that he finds so intolerable in his partner.
It would do many of them good to concern themselves with their own mistakes, rather than those of their partner. Constantly correcting a partner distracts them from monitoring their own movements and perhaps also relieves them of the need to be aware of their own mistakes. 
But even if the know-all actually does know better, he is by means qualified to apply the corrections for mutual benefit.
Neither do teachers always correct every mistake. This is because it is very difficult for a person to concentrate on several things at a time. It is therefore impossible to correct several mistakes at the same time. Those who do not believe this can ask their teacher e.g. to correct their form and point out absolutely every mistake. The teacher therefore decides which mistake is the most important and where to intervene with a correction, but he also decides what is not so important and will not be corrected at that time. But if a training partner now shows up and begins to correct everything he happens to notice, or even something the teacher has just corrected in himself, he is obstructing the learning process.
Of course mistakes also make it possible to gain experience, therefore it would be better to let the student make a mistake so that he learns the consequences. Unfortunately this requires the know-all to be better in practice, so that he in turn can exploit the mistake using his skill and tactile sense. Then both would learn something, one to feel the mistake and react to it, and the other to feel the consequences of his mistake and not just talk about them. Both would train each other more effectively. But unfortunately most people are not that skilled, so they only talk about the mistakes of others by way of at least consoling themselves because they can do no better either.
So use the time to train, not to play teacher. Let your actions speak for you, and make gentle, playful use of mistakes so that you and your training partner really can gain experience. Improve your ability to exploit mistakes rather than your ability to criticise others. You’re your partner will not be able to make a mistake without learning from it. And should a situation arise where training together is not possible because one person’s mistake makes the exercise meaningless, it is always possible to ask the teacher to analyse the error and make constructive corrections.
Just as I laugh inwardly about the know-alls when walking around the class, and also while writing this, why not laugh at yourself a little when you catch yourself being a know-all too, and then: train!

Best regards
Lars Boeckers

The critical voice in your ear

Grandmaster Kernspecht on harmful “self-criticism“

I too have often been irritated by over-keen students who “play teacher“ with others, but Sifu Lars was the first to come with the idea of devoting an editorial to this behaviour.
However, I would like to take the opportunity to discuss a similar form of behaviour which is at least as harmful, though this time for the guilty party himself and not for others. When giving private tuition, I repeatedly find that students find the need to pass comment on what is happening. They constantly and loudly bemoan the mistakes they think they have made (“Damn, I raised my Bong-Sao again“). The left brain hemisphere rigorously criticises everything they do with a running commentary, like some incorruptible external (”I should have done a Kao-Sao there, blast, I waited too long“). They overlook nothing in themselves and can do nothing right. 
In doing so they interfere with my work as their teacher, making the experience less pleasant.  Sometimes I even catch myself defending them against themselves (“Well, it wasn’t all that bad.“, or ”You just need more practice.“)
When I land a light blow somewhere, they immediately begin to explain to themselves what sequence of errors or incorrect responses led to this blow being struck. While I merely put many things down to lack of training and do not consider them worth mentioning, they know better and treat me to an unbroken running commentary. 
They even see mistakes where there are none. They constantly find fault with themselves, becoming increasingly obsessed, rigid and tense. And no wonder, for they are trying to do something consciously that should happen “by itself”. As soon as our conscious mind interferes where it has no business to be, but only acts as a disturbing factor, we become hopeless bunglers.
Particularly in Chi-Sao, the point is to switch off the conscious mind completely so as not to obstruct the autonomous actions of the “feeling” arms. In normal city traffic, even an experienced driver would become self-conscious and drive like a beginner if he felt he was under the critical gaze of a driving instructor. If you become a critical observer of your own Chi-Sao, you cannot give up conscious thought and therefore sabotage your learning progress. Even if you do not make it quite impossible, you are bound to slow it down ...
When somebody delivers himself “into my hands“ so that I can implant semi-reflexes into him, the process is something like a massage. The ”patient“ – the passive connotation of the word already suggests waiting, suffering and accepting, i.e. the opposite of being active – must be patient with himself and leave things to me. My task is to “make“ him good, and he must “allow“ me to do this by leaving his body at my disposal for 90 minutes. Diagnosing problems is down to me, as I have more than 45 years of experience and am paid to do it. So well in fact, that he should think carefully whether he wants to invest e.g. just 2 lessons or as much as 20 lessons in the goal he has set himself.  This is because involving the left brain hemisphere through constant thinking and talking, when only feeling is required, can easily lead to a tenfold increase in the time required. Talking is out of place when it comes to implanting “reflexes“; it is irritating and counter-productive, and does not permit me to help the student as well as I might. I want to be proud of my work and achieve something, therefore I would much prefer it if my “patient“ refrained completely.
Incidentally, other disturbing and counter-productive factors are questions such as: “Si-Fu, doesn’t the technique you performed just now come from the 4th variation of the third level in the 5th section of wooden dummy Chi-Sao, the one that Sigung showed us in Italy in 2005?“
Does anybody really think that I am one of those armchair theoreticians who think about the section it comes from before executing a technique? I don’t “do“ techniques at all. The movement, the landed blow (not really a ”technique“) is provoked and ”powered” by the other person – it is just that I do not go against it. It is only if I subsequently saw a video of what “happened“ that I could tell you in what form or section something like that “occurred”. But I did not “do“ it because it “occurs“ somewhere, but because this movement was ”strongly suggested” to me.
My advice is therefore to make my work easier and speed up your progress by forbidding your mental process from involving themselves in my ”Chi-Sao massage“. Relax and enjoy!

PS: Now a good dozen or so of my private students will be thinking: "Si-Fu means me, because last time I ...". In fact I don't mean anybody in particular, or I mean them all.
And to avoid giving the wrong impression: I am very happy with my private students, and enjoy working with them.