
Proofing is the final step in training your dog in any new behavior. It involves practicing behaviors in a variety of situations with different levels of distraction. You want your dog to stay wherever and whenever you give the command, not just in the room where you trained it, and this takes practice.
To understand why proofing is important, you must first be able to understand how your dog thinks. Dogs aren't able to generalize the way people do. This simply means that your dog may understand what sit means when you give the command in your kitchen, but it may not understand that it means the same thing later on, or in a different place.
Failing to proof behaviors is the reason why your dog may perform behaviors well in your living room, but seem to forget all its training the minute you leave the house.
Think Like a Dog
To understand why proofing is important, you must first be able to understand how your dog thinks. Dogs aren't able to generalize the way people do. This simply means that your dog may understand what sit means when you give the command in your kitchen, but it may not understand that it means the same thing later on, or in a different place.

Imagine you are sitting at your dinner table, and your mother says, Get your elbows off the table! When she says this, you understand that this is the rule for all tables. You need to keep your elbows off this table and the table at your aunt's house and the table in a restaurant.
But if you were able to tell your dog to get its paws off the table or stop begging, it would understand only that it wasn't allowed to put its paws on this table or beg at this spot. Dogs are not able to generalize, so they won't understand that the rule applies to every table.
When your dog is able to perform a behavior on command as perfectly at the dog park as it does it in your kitchen, you can consider the behavior proofed.
Add Distractions
When you begin training your dog to do something new, you usually start off in an area that's fairly quiet with very low distraction. Once your dog is able to respond quickly to a command in this setting, it is time to add some distractions and new settings. Do this slowly, and work on adding one new thing at a time.

For example, practice the sit command until your dog is able to respond fairly quickly. Then begin to slowly add some distraction.
Have another family member come into the room. Practice several times, and then turn on the television while you practice. Slowly add more distracting things to his environment, like other dogs, running children, and loud noises. Do all this while practicing the sit command.
Practice in Different Settings
Once your dog is able to follow the new command with some distraction, begin practicing in different places, such as another room, the backyard, and the neighbor's house.
For example, stop in the middle of walks and command your dog to sit, and even practice at the dog park, the vet's office, and before getting groomed. Proofing a behavior means making sure a dog understands a command regardless of setting.

Keep each training session to about 10 minutes, and stay upbeat even if your dog acts in the new setting like it never learned the command in the first place. It should now be able to perform the behavior as well at any location as it does it in your living room. Once you've gotten to this point, the behavior is proofed.
Be Patient
If your dog is struggling with a behavior, after about 10 minutes have gone by, you're probably not going to get it to complete the action. End the training session with an easy command it already knows, so your dog doesn't feel like it's being punished.
Resume the training when the dog has had a break and can concentrate.
Problems and Proofing Behavior
One of the biggest mistakes owners make when training their dogs is inconsistency. If a dog is not allowed on the bed, but you occasionally let it come on the bed, you're not reinforcing the rule, and the dog will remember the instance when it was allowed on the bed.



This is how a lot of dogs learn to beg at the table. Someone, at some point, has dropped food on the floor or fed the dog from the table. The dog remembers that instance and will wait for it to occur again.
Being consistent with training also means being thorough. If you command your dog to sit, and it only sits for a few seconds, or gets halfway down on the floor but doesn't actually sit down, this is not behavior to reward. Instead, keep practicing the command until the dog sits and remains sitting until you reward it.