onthefence, the reasons that "other jobs educating children have paper qualifications" are probably very similar to the reasons why coaching licenses were created. but, with teachers, i believe at least a couple of the ways to ensure you not only have a qualified (certified) teacher, but also a "good" teacher is through direct assessment, i.e., another teacher sitting in the classroom during the day; and student testing, to see what and how much the students have been taught (education experts, please feel free to correct me on this)
with coaching, i believe the process is much simpler - if you are not a "good" coach, people are either going to complain about you (which happens even with good ones) or they are going to go elsewhere. it's kind of a self-fixing problem. word gets around - if the coach is "good" he/she will find work. if not, they will probably spend all their free time on bulletin boards, trying to stir up trash about the ones who are.
