No bones about it, dog training has come a long way through the years. In the past, very forceful, sometimes brutal methods were used to get a dog to respond to commands, ranging from physically pushing the dog's hips down to teach him to sit, to "stringing up" dominant dogs to teach them who was boss (i.e., physically choking the dog by lifting the him off the ground by the leash).
And the scary thing is, some of these books are still in print, being sold to inexperienced dog owners across the country. Case in point, there is a book still on the market that was written decades ago by one of the top dog trainers in Hollywood at the time. This trainer's method of curing a stubborn dog from chewing was to take a piece of the material that the dog had chewed, putting it in the dog's mouth, and then taping the dog's muzzle shut for long periods of time. The rational for this barbaric behavior was that by forcing the dog to hold the material in it's mouth, it would get sick of the taste and no longer want to chew on it. This book also advocates stringing a dog up, which can severely injure the trachea or even kill.
Luckily, things seem to be changing for the better as more positive and certainly less traumatizing methods become more and more popular. Much of the training is reward based, meaning that the dog is given something he wants in exchange for performing the correct behavior. A dog who is motivated by food can do really well. Since most of the Rotties that I've known would gladly paint the Sistine Chapel in return for a treat, I've had a lot of good results with both Chelsea and Sephie when I've used positive methods with them.
One very important aspect of training is to have a "marker". A marker is a signal to the dog, telling it exactly what it is being rewarded for. For an illustration, all you have to do is look at where clicker training originally came from.
