Conventional trainers start teaching a dog to sit by saying “Sit” and expect the dog to sit. Because the dog does not understand “Sit”, they then push the dog into a sit and repeating “Sit” with increasing intensity. The dog learns that if he wants to avoid being pushed around or yanked with a leash, his best option is to put his butt down. This is a form of negative reinforcement and enables learning with repetition. But does the dog enjoy learning this way? Using this approach, will your dog happily come to you when you ask him to come?
In positive dog training, we teach the dog the behavior first before adding a command to the behavior. A conditioned positive reinforcer is guaranteed to lead to reinforcement because the dog happily wants to get the treat.
Preferring a positive approach is actually similar to how humans work. If your manager ask you to do something and is grateful for your help, you will want to do work hard for your manager. If your manager is nasty and orders you around to do stuff, you might do it. But once your manager is assigned to another department, you will most probably reject him.