In addition, the knowledge presented is usually advocated as a prescription for better teaching. The PLCs model represents a fundamental shift away from this traditional model of professional development. PLCs at their best are grounded in generation of ‘‘knowledge OF Practice’’ (Cochran-Smith & Lytle, 1999). That is, ‘‘it is assumed that the knowledge teachers need to teach well is generated when teachers treat their own classrooms and schools as sites for intentional investigation at the same time that they treat the knowledge and theory produced by others as generative material for interrogation and interpretation’’ (p. 272).