Your job is to find out what food or toy rewards are meaningful enough to your dog to make him want to play the game with you. And training really is a game to the dogs and you too!
Psychologost Skinner called the tiny steps in developing a new behavior “successive approximation” and he was right! If you reward really simple behaviors that are part of a more complex behavior, you can get the dog to change that behavior little by little into the more complex final behavior. The dog is “approximating” a behavior at first. Today we call this "'shaping".
Shaping a Behavior
If we first asked your dog to shut the door and just waited for the behavior to happen, we would be waiting a long time. So that method doesn’t work for this complex behavior. But by asking the dog to do a tiny bit of the behavior (touching the nose to the door), we now have the dog doing something that will lead to closing the door.
Next, we ask for a harder touch (as this will be needed to shut the door). Next we can open the door a crack and ask him to push it closed. If he does not, we can get the dog to increase the behavior by simply waiting. Your dog will likely offer another touch, giving an extra hard push (as if to say, “Hey! Did you see that?”) and you click as he does so. If you reward him with a couple of treats, most dogs remember this and are more likely to do that same harder push again.
Practice at that level for a few clicks, then ask for a little more by opening the door slightly wider. And so on until the behavior is complete.
Have a look at the video to see how shaping is used to teach a dog to close a door.
A Written Plan
It is very helpful if you have a written plan of what the shaping might look like before you start training a task. Start by brainstorming: at the bottom of the page, write down the final behavior you want, then at the top, write down the first behavior you would think your dog might offer you. Most behaviors start with a sniff or a look in the right direction, the progress to a nose touch, paw or other foot movement etc. Try to figure out what the steps would look like in between to get you there. Number them if it helps. You dog may not follow your plan, but at least you will have an idea of where to go with what he does offer you. If you get stuck, break each step down into 4 more micro steps. Make it as easy for him to take each small step as you can as this is how you can quickly progress to the more complex final behavior.
Jessie learned the basic idea of how to close a door in about 30 minutes of actual training time when she was about a year old. We had not done much shaping before this so it was new to her. I was cooking her treats on the BBQ and needed to take frequent breaks to check the meat. This was perfect as it gave her a chance to wander off and sniff, then she was eager to come back and try again. Perhaps she was processing the information she was learning.
For some dogs, shaping occurs quite quickly, while for others (especially the first few shaping exercises you do) each step may need to be broken down even simpler. The more experience a dog has with shaping, the more quickly the final behavior is offered. Now at almost 2 years, Jessie can move through a shaped exercise quite quickly and has the final behavior accomplished in record time (for her).
For practice before trying to teach your dog to shut the door, try shaping a firm nose touch to a piece of tape on your hand. Then try moving the tape to the door. Your pointing finger becomes a target to help the dog to learn that you him/her to touch the tape.
What Else Can I Do with Shaping?
Now that you know how to shape, the world is your oyster! You can train your dog to do anything! Start with simple behaviors and progress to more complex ones. Starting with Object-based shaping where your dog interacts with a physical object such as a target, book, chair, box etc is much easier than non-object based shaping like swinging into a heel position or giving you eye contact in distracting environments.