My children attended a charter high school run as a teacher's co-op - no principal or formal administration. It works very well, although I'm not sure it would scale as a model. Certainly, I've never seen such high levels of teacher satisfaction anywhere else, and I'm sure the cost of a principal and assistant principal easily funds three more teachers - a big deal at a small school.
Interesting, was this a primary or a secondary school?
I ask because teachers in secondary schools seem to be under much more pressure to ensure their students pass standardised exams to enter higher education, whereas there's much more wiggle-room for alternative methodologies at younger ages. It'd be good to see some innovation at the secondary level, rather than just attempting to keep up with what examiners require.
Secondary. Grades 7-12 (the school has since added 6th grade).
Minnesota's charter system is (or should be) a model for other states. There's lots of interesting education innovation going on here. Lots of failures too, but that's what happens when you open the doors to innovation.
Besides being a co-op, Avalon is a project-based learning environment. This requires a great deal more personal responsibility on the part of students for their own educations. It wouldn't work for most students, but for those who do well there, it shines gloriously. That's what I love about charters, really - the opportunity for educational diversity, and finding models that work well for different kinds of students and different kinds of teachers.