You must train your dog in every environment that you expect them to behave in, but you have to start with the basics.
The beginning of our training should always be conducted in a distraction-free environment. You can use your backyard, garage, basement, living room; it doesn't matter, as long as it is a neutral and distraction-free environment where your dog can focus on you and not be distracted by outside influences.
This video was taken from our newest DVD, An Introduction to Dog Training with Jeff Frawley.