Why is there such a large turnover in teaching materials and curriculums in our public schools? I would think that it is counter productive.
It would seem to me that oce you found a method that works you would stick with it. The money spent on new materials and training for the new curriculums must be astronomical.
Why you ask? Because the publishing companies make money off of selling new curriculum books. You can thank the publishing companies’ lobbying of state governments and congress for a huge part of the cost of public education.