Bringing training to heel
Whilst I am certainly not into harsh handling of dogs, or any animals for that matter, I am not convinced that 100% rewards based training is the idea either. I have never seen so many ill behaved dogs, dragging their owners around whilst only stopping occasionally to look up fondly into their owners face demanding yet more food. The following article from UNDARK is quite comprehensive and presents some different perspectives. I did find it interesting that the recall research cited, involved dogs on leads. This is usually a good starting point for recall, but true recall should be off lead to test a dog properly.
Punishment, Puppies, and Science: Bringing Dog Training to Heel