“Any student in experimental psychology has done at least one cognitive computer task where the computer gives feedback for accurate (sound A) or inaccurate (sound B) responses. This is typically done so the subject can update its knowledge of the task and change its response pattern to increase performance. Is it not fascinating that the same idea will repulse many trainers? The idea of saying (softly) “no”, or “nuh uh” or use a non-reward marker (a very fancy terminology to say “punishment”) seems to get people all up-in-arms. Why? Well, technically, if “no” means “that was not the right choice” or “don’t do that again”, and the dog does not repeat the behaviour… it was a punishment. It is actually what I like to call information. Simple. We like information as humans, because it accelerates learning, it helps us make sense of the world, it helps us make sense of a set of rules in a game. When I was learning classical guitar in the 70’s, I was very happy to have my teacher tell me what I was doing right, and what I was doing wrong. It was less frustrating to know about my mistakes, than trying to guess what I was doing wrong. He was paid to tell me this. Why do we deprive our dogs of that information?”v

http://doyoubelieveindog.blogspot.com.au/2015/04/51-shades-of-grey-misuse.html?m=1#.Vj9wHitz_fb