Of course, the traditional school system is at odds with the very spirit of collaborative learning. Schools, as they were conceived and as they are still administered, are essentially authoritarian constructs.
"Lectures" are the preferred method of teaching and the formal physical, emotional and psychological set-up of the traditional classroom is confrontational. Teachers are still equated with "discipline" and "consequences." They are the transmitters of knowledge and the evaluators of the students' grasp of the information they have "given" to the students. They are the regulators of the competition that is encouraged between students through the assessments and recognition and rewards for individual achievement.
"Conversation" is discouraged in traditional classrooms where learning is a solitary pursuit of an individual student faced with the information being given to him from the front of a classroom by a teacher who is the expert instructor. There are definitive syllabi for every subject with course content to be covered in a set period of time; there are lecture plans for every teaching hour and teachers are under pressure to ensure that their students have ingested the carefully planned and delivered information and are capable of regurgitating it as required during formal assessments. Memory is more important than assimilation.
In collaborative learning, on the other hand, the process of learning is basically more important than what is learned. Students are taught, by hands-on experience, how to learn and not what to learn. When they learn, assimilation of the material is an absolute requirement as a student must take the material, absorb it, make it his own and then present it or teach it to others. Mere memorizing will not help the collaborative learner.