It was a great experience for me to do the RSM model building an online course. I learned experimental designs for fitting response surfaces.
The course tries to cover a lot of material that is somewhat math-heavy. It's not easy to digest some of the concepts without some self-study using the book. Exercises and quizzes only cover a fraction of what is taught. An improvement could be to cover less topics and use the time gained to give some more examples and clarify some of the math.
