"These systems also establish collaborative practices between teachers within and across
schools that emphasize making practice public – such as weekly lesson-planning for all teachers in the same subject, required lesson observations, and joint-teaching – that serve to perpetuate and further develop the established pedagogy"
—“How the world’s most improved school systems keep getting better” Executive Summary p. 4 http://www.mckinsey.com/clientservice/Social_Sector/our_practices/Education/Knowledge_Highlights/How%20School%20Systems%20Get%20Better.aspx
