I have to wonder if flipped classrooms make teacher time in class more inefficient because the teacher's search costs of grouping like questions rises. Along the lines of Zen Scanner's earlier comments, if 5 students have the same question but are unable to stop the teacher in real-time to voice their question, how long does it take the teacher to first identify the students with similar questions and, second, actually address the underlying misunderstanding? It's not like students will line up based on the time in the video where their questions first arose.
I think flipped classrooms ignore the path dependency of learning. Learning, IMO, arises from an endogenous dialogue between the student and teacher, and flipped classrooms assume there is a fixed linear path for learning for all students. It sounds like the method could, if used incorrectly, actually become less adaptive to individual needs than traditional methods. I also echo DeeDee's concern that the model over-assumes teacher ability to effectively differentiate.
That is
precisely what happens.
MOST college STEM laboratories are taught as more-or-less "flipped" and always have been.
It is incredibly inefficient, however-- because you'll answer the same question about four to six times in a four hour lab-- each student requiring a 15 minutes explanation while their classmates wait for you.
My personal experience suggests that ONLY struggling students get teacher-time in that model. Now, the argument can be made that this is appropriate, but I think (as parent to a giftie) that this is morally WRONG. Advanced students who are NOT struggling to master the basics ought to get some love from the expert, too, KWIM?
The other thing that a flipped classroom does is deprive students of the opportunity to learn from the questions of classmates-- or to simply check their own understanding (by comparing their answer with the instructor's).
I'd argue that students who are at a predictable and uniform learning readiness and background knowledge are
least in need of an expert live teacher-- that's sort of the point, that canned video makes a series of assumptions about preparation and level of ability to learn at a particular pace and with a particular level of detail offered. Those assumptions are not necessarily true for non-normative students.
If you have a class of 30 students, it may well be that four of them have a single question about the same thing because of a common feature in their background as learners.
OR-- two of them may want to know if {alternative viewpoint} is equally valid, in light of {other information}. Perhaps one wants to know if the current topic is correctly associated with {this other thing} via {mechanism/connection}.
Those are the kinds of things that make class interactions with a subject expert highly worthwhile, and truly-- far richer than a canned video watched at home with the TV on for background noise.
I'm sad that so few people have apparently experienced an open- or soft-lecture format, where pauses for reflection/interaction/application are common. A supportive environment like that is REALLY superior to either a pure lecture or a completely flipped classroom, IMO. It's better for both tails, and WAY better for the center of the distribution, too.
I also think that it does a better job of fostering a positive learning community-- which DRASTICALLY improves teaching efficiency-- where students communicate with one another dynamically about class material.
I think that it is tempting to assume that flipping a classroom results in self-pacing, but that is NOT the case.
Nor is it the case that flipping classrooms makes differentiation or ability-grouping easier or more likely.