This paper attempts to provide: (1) a clear mental image of the concept of a professional development school (PDS); (2) a clear understanding of a number of standards to be considered as guides during the decision-making process which goes on as a PDS is designed and implemented; and (3) insights gained from dialogues with faculty members of a Rochester, New York, secondary school who had been exposed to the concept of a PDS and were considering the possibility of establishing a PDS. The image of the PDS which is articulated is based on the fundamental assumption that improvement of teaching and student learning cannot continue to be driven from outside; "top-down" decision making has not been effective. In order to develop a PDS organizational structure, certain standards should be employed for local decision making: students must learn how to go about learning; high quality education must be available to students from diverse backgrounds; school faculty and teacher educators are expected to go on learning, developing, and renewing themselves; and in the PDS, continual reassessment, relearning, and redesign go on. (IAH)