Now, How would you explain to a 5 year old that thumping dogs on the nose for control, using excessive force (shoving into a down for example), repeating commands (sit, sit, SIT!), using more correction and reserving praise......how would you tell a 5 year old all the things that are wrong with the above?

I'm training Zak and he's a normal 9 month old Rottweiler, bullhead (though less so than most) with selective hearing. But my Dad keeps interfering and I'm afraid he's going to ruin Zak for good for any working potential he may have.

He use to be an apprentice trainer some 20 years ago in his 20's. Obviously methods have changed since then !

He thinks they work, and sure their fine for pets (which is all he trained) but not for what I want for Zak. He also uses NO! in every context, without explination. Instead of "no bite" he just says no, instead of Out Zak, he says NO...its ridiculous!

How can I explain to him to BACK OFF and explain why these things don't work any more. I said explain like a 5 year old because thats how closed-minded he is.

Buy Eds basic obedience video. Tie him to a chair and force him to watch it until he gives in. Or take him to a local club so he can see how we train in the 21st century.
Good luck, it takes a big man to admit he's been wrong for 20 years