Based on experience, it seems to be how it actually works in practice more often than not, though. I agree that in an ideal world, such a teacher would be delighted and care not a bit whether the entire discussion were more or less over the heads of many classmates-- but that's not the world that my DD finds herself in.

The result is that DD has to opt to stay at the watering hole with the rest of the herd...

or choose to learn in a vacuum, with occasional input from a mostly distant teacher who is still teaching the middle of the distribution, albeit one with a higher mean than in a standard setting.

I can see the teacher's point, here, myself. A discussion which is beyond the ability of most students to follow, much less participate actively in, is probably not a good use of group instructional time.

But that does leave students who learn best in groups out in the cold unless they can conform to what classmates are ready for.



Schrödinger's cat walks into a bar. And doesn't.