I have been asked many, many times over the course of my career as an instructor ,why do students need to take a formal test in order to advance in rank? I understand the reason for this question. You taught me the material so you know that I know it from working with me in class. Why require me to take a formal test in order to show your that I know the material?Some martial arts do not require a formal test. A student is awarded new rank in class when the instructor deems