My shodan test took a little over an hour. It was very unpleasant. LOTS of stress! My nidan test took 45 minutes. It was only mildly stressful. What a difference three years of training can make! Kawahara Sensei told me when I would test. Any remaining tests will be at his invitation only. If you do a technique correctly you do it only once or twice. If not, you are forced to repeat it until you succeed in proper performance of it or he gets fed up and tells you to test again at a later date (fortunately this has never actually happened to me). The yudansha test requirements encompass about 200 techniques (above and beyond techniques learned for earlier tests). If you are doing really well he sometimes asks for as many variations on a technique as you can supply. The testing seems more and more like a formality as I test for higher and higher ranks. I think maybe sensei knows before I test if I'm going to pass or not.