this is a very tricky question.on one hand some jerk can read a few issues of "black belt" and try to teach a class and promote himself to "soke". first of all i would ask questons about the instructors training, if he replies that he learned in the shaolin temple in a top secret location, run...run as fast as you can. If the instructor is 20 years old and a 10th degree black belt, a red flag should go up. However, i must say that just because a style is new doesn't mean that it isn't real. look at bruce lee, he developed JKD, was he qualified??? Ed parker totally redone Kenpo Karate when he came to the u.s. to teach it. New styles are what america is all about. Some want to learn an ancient art that is taught the same way it was 1000 years ago, some want new and modern techniques developed for modern times, it is a judgement call. Jhoon Rhee is teaching, "american tae kwon do". the creator should be at least a 3rd dan or higher,have approval from his instructor to borrow from the style, an last but not least the style should be tested for quality.