"Punishment" in the Operant sense, is anything that reduces the likelihood of the behaviour being repeated. It is the opposite of "Reinforcement", which means anything that increases the likelihood of the behaviour being repeated. While we are at it, "positive" means something is added, "negative" means something is taken away. I know I am belabouring the point, but the terms are quite specific and incorrectly used more often than not by both trainers and lay people. Which wouldn't matter except it causes confusion when people use the term incorrectly and so are misinterpreted by others who do understand the definitions....
