I think the approach should be different based on the dog and the breed. Not all dogs learn the same and the owner/trainer must use the method, or combination of methods, that work best for their dog and situation. I have used force and positive reinforcement at different time. There are times for both and the talent of the owner/trainer to know which to apply in a particular situation is where the best learning will happen. When to be firm and use dominance over the dog or when to be the giver of good things.