Suzannahnoelle 

well said.  Your very last point is well taken.  As in most things in life it is not the tool, we use but how we use it. The full and half check collars are great tools that are effective in correcting a trained dog.  It is therefore important that the dog understands the meaning of the collar.  It provides both an audible and tactile cue when a correction is necessary, and the dog will learn this very quickly.