Traditional models of professional development have focused on providing teachers with the skills and knowledge necessary to be ‘‘better’’ educators. These models have typically been grounded in the assumption that the purpose of professional development is to convey to teachers ‘‘knowledge FOR practice’’ (Cochran-Smith & Lytle, 1999). That is, the professional development activity is based on the premise that knowledge and expertise are best generated by university researchers outside of the day-to-day work of teaching. Through professional development, teachers acquire and then implement this knowledge. 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).