[DarrinGreene]

It's the stage when you start using aversives to re-enforce behavior. When to start it depends on the temperament of the pup in question. In the pet practice I have had dogs that not only were tolerant, but IMHO needed formalization at 12 weeks of age (yes 12 weeks) and others where aversives put so much stress on the dog that they were never used (that dog would be washed out in most retriever applications).

The only thing consistent about when to start, and this is a belief of mine as opposed to a rule, is that the dog needs to demonstrate proficiency in a given behavior using motivational methods before I will add anything aversive. The single exception to this being how to walk with a large dog that's out of control on the end of a leash. In those cases many time the use of a pinch collar is like magic to the client.