In the past thirty years public administration has developed more systematic patterns of inquiry about the substance of public organization behavior, public management, and public policy implementation. This work has contributed to an increasing reliability in understanding public administration. The work of public organizations has been examined with improved conceptual methodological and theoretical forms of analysis. The forms of analysis seek to create knowledge that is retraceable, cumulative, and at least at some level, replicable. These forms of analysis aspire to be scientific, using scientific here to mean a kind of formal rationality by which the insights of the next generation. Knowledge, then, becomes collective and cumulative. This is not to suggest that the social world, of which public administration is a part, is as amenable to formal scientific applications as is the physical world. It is not. But it is to suggest that the art and science of public administration should be just that - both art and science. The science and art of policy administration is definable, describable, replicable, and cumulative. A further purpose of this book is to describe in some detail several theories and analytical approaches that contribute to what we know about policy administration. If we can accept that each approach to the subject of policy administration is guided. At least in some rudimentary way, by a theory or set of theories, the questions are: Which theories or approaches are the most promising, the most influential? Which are the most important now and likely to be the most important in the future? The purpose of this effort is to set out a detailed description of the author's selection of key theories in contemporary public administration in the hope that this will improve the reliability of our knowledge and our understanding of public administration. This primer is designed to fit into Public Administration Theory courses at the advanced undergraduate level, as well as for courses in the MPA curriculum.