Housetraining Cairn terrier

Question
We have a 12 week old Cairn terrier male. He's just adorable, but doesn't seem to be getting the hang of going outside to eliminate. Often he'll be outside for a time, and immediately relieve himself as soon as he gets back in. Does he feel more comfortable inside? We work with him as best we can, and when catching him in the act, simply say his name (Peanut!), followed by "OUTSIDE!" and then carrying him out to the yard. Any tips? Thanks!

Answer
Do you have access to another dog?  If one of your neighbors has a nice male dog that can come over. Have him  pee with your dog there to watch and smell the urine outside.  Often little ones need to imitate or just needs a little inspiration.
If you can't watch him while he is outside you can crate him again for a bit when you bring him in the house and then repeat the process of putting him outside again till you KNOW he has gone.  
You can put him on a leash in the house and have it in hand while he is in there.  When he assumes the position gently tug it saying NO NO and pull him outside where he can finish the job while saying GOOD BOY when he does.
Some people use those wee wee pads outside.  I haven't tried that one yet.  

Hope this helps and good luck........