There may be as many answers to this question as there are dog trainers. I have my own ideas, of course. I like to think I follow this logic:
To use shock as an effective dog training method you will need:
A thorough understanding of canine behavior.
A thorough understanding of learning theory.
And if you have those three things, you don’t need a shock collar. –Author unknown
In my opinion, and many others, this logic applies to tools and methods dogs may find aversive, not only shock collars. There are SO many options before aversives are applied, that a good trainer would never need to use them. That said, I do use head halters as an occassional training tool but want my clients to work out of them.
For your perusal and thought:
LEIBI. Version 6.0 (AABP)
WHAT’S WRONG WITH THIS PICTURE? EFFECTIVENESS IS NOT ENOUGH (The origin of CCPDT’s Humane Hierarchy)
The “Humane Hierarchy” for animals may have been based upon a similar treatment hierarchy for developmentally disabled people. I can’t find the original source.