I think evaluations are in fact useful. I have given evaluations to many professors and have seen tangible differences in their teaching. Some actually welcomed feedback.
Perhaps the lack of correlation is attributed to the lack of accountability in universities in holding professors to making changes in teaching style. I laugh when I say that because so many professors aren’t really teachers, just PhD’s that with poor communication skills.
What’s the correlation between learning and actual training in teaching STUDENTS? Maye that should be looked at instead of evaluations. I’ve seen articles published by professors claiming their role is to “broaden the knowledge base” and almost practically administrate a course with a few slides and tests. If that’s the case students should all get tuition discounts for “teaching” themselves.