Tomorrow 's Schools (1990) is the second report in the Holmes Group's trilogy on the reform of education in the United States. Centrally focused on the improved preparation of teachers, the three reports offer a vision of a new institution, the professional development school (PDS). Although the other two volumes, Tomorrow's Teachers (1986) and Tomorrow's Schools of Education (1995), discuss this new institution, the second volume elaborates on principles for its design. Given the growing popularity of the concept, the growing numbers of PDSs and PDS networks, and the work of the National Council for the Accreditation of Teacher Education in developing PDS standards, a close examination of the design principles and related research seems warranted.While other reviews of the research have been conducted, this one differs in three fundamental ways. 1 First, it attempts to match the goals set out by PDS proponents with changes documented through research. Second, it seeks to determine whether those changes are what Cuban (1988) calls first-or second-order change. Finally, it specifically relates these PDS goals and changes to equity goals. Equity has long been a cherished, albeit controversial, goal of American education. It is also a driving force behind the vision for PDSs as articulated in Tomorrow's Schools. Therefore, a question worth asking is, What, if anything, would enable PDSs to accomplish a goal that has thus far eluded most of our nation's schools?To answer that question, we begin with a definition of PDSs, an explanation of first-and second-order changes, and an overview of equity as a concept in educational literature. We then review both the advocacy and research literature on PDSs under six themes we have identified and extract equity implications. The specific questions guiding our research were as follows:1. What does the literature say about aspirations for PDSs? What do proponents hope and claim these new organizational structures can accomplish? Are these first-or second-order change aspirations? 251