dogs generally like to poop in a spacious area. also they generally poop after eating properly. so make sure that you give food at a specific time so that his digestive system gets used to it. once your dog eats food, then take him out for walk. and walk him till he poops. when he is doing it, say potty...good boy...appreciate him...do ths regularly and he wl poop outside. second method is to crate train your dog. put him in the crate for 3-4 hours (the crate should nt be too small for the dog) and then take him out of ur house, wher u want him to poop. and dnt take him home till he is done...hope this works for u. i never had to crate train my dog. my dog likes to poop in open space, and it was a little difficult bt nw they poop outside.