I've been thinking about this through the day and it really may depend on the domain being taught. A non expert may be able to teach a well defined skill step

I've been thinking about this through the day and it really may depend on the domain being taught. A non expert may be able to teach a well defined skill step by step better than someone else who performs those steps without thinking about them anymore. I've done too many years of math tutoring to know that the non experts in math teaching math are not doing a consistently good job. A non expert in a complex field has no way of teaching off script -- which is where a lot of students will end up entirely by accident. I see it all the time tutoring math. I'm helping students who wandered from the one way that it was being taught. I help them get back some understanding when they feel lost trying to execute algorithms to solve problems. The article is very long on assertions and short on everything else. The final argument against this in my experience is that experts blow away non experts on fundamentals. Sports, math, science, writing, cooking, construction, painting etc...