In the twentieth century, formalized dog training originated in military and police applications, and the methods used largely reflected the military approach to training humans. In the middle and late part of the century, however, more research into operant conditioning and positive reinforcement occurred as wild animal shows became more popular. Aquatic mammal trainers used clickers (a small box that makes a loud click when pushed on) to "mark" desired behavior, giving food as a reward. The change in training methods spread gradually into the world of dog training. Today many dog trainers rely heavily on positive reinforcement to teach new behaviors.
When observing a class, take note of the dogs; do they look happy? Relaxed? Excited to work? Is the instructor encouraging dogs and owners? Does the class seem to be run in a safe and effective manner? If you don’t feel comfortable at a particular training school, your dog won’t either, and you’ll be setting Fido up to fail. Keep looking for a school where you feel comfortable; you and Fido will do your best work this way!
Remember that training is an ongoing process. You will never be completely finished. It is important to keep working on obedience training throughout the life of your dog. People who learn a language at a young age but stop speaking that language may forget much of it as they grow older. The same goes for your dog: use it or lose it. Running through even the most basic tricks and commands will help them stay fresh in your dog's mind. Plus, it's a great way to spend time with your dog.