Re: Beginners Retention Rates
I don't mean to be contentious, but I think this is a wrong question to be asking. As an instructor I prefer to stay focussed on what I need to teach and how best to teach it so that those who want to learn will get the best chance to do so. This may seem the same as thinking about student retention, but it isn't. It is not my job to "keep" students, it is their responsibility to learn. The only exception would be kids, and I don't have children's classes.
Other recent threads have addressed the idea of "basics" in Aikido. If a dojo is strongly focussed on Kihon, everyone, including beginners, will benefit. The temptation to make Aikido easier to attract and hold students, IMHO, is as dangerous as doing "advanced" techniques to hold and please senior students who are no longer improving through the study of the essentials.