I worked in an open school at one point, and it was used by staff to collaborate and differentiate...but the first thing every teacher did with his/her space was to put up barriers (bookcases, additional white/chalkboards, drapery, etc.). We also quietly placed certain children into the few closed classrooms in the building, including all of the kindergarten and first-graders.
I will say it was fabulous for classroom observations, though, as I could stand on the third floor balcony and observe student behavior on the first floor, without anyone knowing who I was observing. (This was an all-in open school, with one enormous, cavernous open space on three levels. Including the school library.)
