Here is what happens in my classes throughout the year:
2. Direct instruction
3. Group work
4. Inquiry and problem-based lab assignments
5. Traditional worksheets and HW
6. Collaboration on nearly all assignments
7. Alternative assessments
8. Traditional Tests
9. 1:1 instruction with the teacher
10. Peer instruction almost daily
Do all of these happen every day? No way. I transition my students so that by the end of the year nearly every one of them happens in every unit.
The problem that a lot of people have with the Flipped Classroom is, to take a mass media perspective, 'the teacher lessons are recorded on video, which is watched at home, and homework is done in class instead.' While this does happen, this is the most elementary view of this model. Most of us who have been using FC for more than a year have adopted a large number of alternative methods to use for both instruction and assessment, and are insulted when what we do is boiled down to the above sentence.
But what has been really bothering me is the fact that so many refuse to even see the Flipped Classroom for what it CAN be: a better use of face-to-face time with the students. This system doesn't work well for every kid. But, guess what? No system does!
There are teachers who are absolutely amazing lecturers. Decades of teaching have given them an amazing presence in the classroom and their lessons are mesmerizing. But many students don't connect on a personal level because they limits student engagement. I have seen teachers whose students score 4s and 5s on the AP exams year after year, but who hate the subject matter when they leave in June.
Here's my point: I don't care what method you use (UbD, POGIL, PBL, or pure traditional), if you are doing what is best for YOUR students then you are ok in my book. But, don't assume that your way is the only way or even the best way. Be open to new ideas and be willing to accept others for doing it differently.
For more information, here are a couple of great links that show that the Flipped Classroom can't be summed up in a simple definition:
15 Schools Using the Flipped Classroom
Flipped Classrooms: Let's Change the Discussion
The Flipped Classroom: Pro and Con