This action research study sought to investigate a sample of urban Catholic school teachers\u27 perceptions of how an exploration of differentiated instruction through embedded professional development changed their traditional one-size-fits-all pedagogical practices to a model that addressed students diverse academic needs. Research studies provide evidence that a one-size-fits-all recipe of instruction continually fails to build students’ capacity to learn. Interviews are the primary source to elicit teachers\u27 perceptions of changed pedagogical practices. In conjunction with classroom observations, a focus group formed to better understand the rationale for the principles of differentiated instruction, make sense of the practice, and determine if new knowledge changed participants\u27 thinking and behavior about teaching and learning. Findings indicated that research, workshops, reflection, deeper conversations, personal mastery, and shared visions within embedded professional development transformed the culture of instruction. Further, in an attempt to explore the many dimensions of differentiated instruction guided by my actions as the school leader, participants freed themselves from habits of isolation, created the foundation for a learning community, and built professional and personal efficacy
