Any conception of staff development emerges from an understanding of teaching, schooling, and education. The way people define and think about staff development will be influenced inevitably by their philosophy of education: their values, beliefs, and their taken-forgranted assumptions about what is and what ought to be. Clearly, education theories, interpretations of research, and experiential considerations impinge on educators' ideas and actions. Thus, these three broad frameworks must be illuminated in order to examine staff development. This work explores these three major sources of conceptions of staff development: theory, research, and analytical reflection of educators' experiences. It offers fresh insights into teaching and schools as well as a broader and more powerful conception of staff development.