I've used Recorder Karate for several years now. I have found with the first three or four belts, you can test three students at a time, and it is just as efficient as (and less time-consuming than) testing one student at a time. After the third or fourth belt, and with their classroom teacher's approval, students can come in on their own or with two other players to test after my last class (which is usually 30 minutes before dismissal). If necessary, I am still able to work with individual students when three test at a time.