I remember more than twenty years ago having a conversation with a teacher who was the wife of one of my friends. She was a very nice person and devoted to her job. I brought up the subject of the habit that was being initiated of putting slow or troubled kids in regular classrooms....mainstreaming or some phrase like that.
I asked her what good would it do if the other children had their education disrupted by the troubled kids? She was adamant that the troubled or slow kids needed to feel wanted. I said, that's fine, but what about all the other children. She just repeated her mantra about not excluding the troubled kids. I gave up.
I taught an embedded systems course for 3 1/2 years. I structured it as self paced with 3 hrs lecture and 4 hours lab. The best students finished work ahead of the average. I rewarded them with more intricate challenges. They returned the favor by helping to tutor the slower end of the group. The course was co-sponsored by the college and the Regional Occupational Program. ROP tracked successful hires from the program. 91% of my students were hired by DEC or IBM over the 3 1/2 year period. I stopped teaching when my software work at PacBell left no room for outside work.