Teaching 'back up'

This is a little trickier.  You need a narrow space where the dog doesn't have room to turn around..    Call the dog forward to you , then walk forward toward/into the dog, using the command.  When the dog backs up to get out of the way, say 'Good back up!' and treat.  You will need to work more on this before the dog will do the behavior out of the 'tunnel'- Tali is still working on that..  :)