The hypothesis is the device scientists use to translate questions, theories, or proposed explanations into a form amenable to empirical research. This edition of W. W. Charter's treatise on clear, conceptual definitions and precise operational hypotheses, which was originally developed to assist students in educational policy and management courses is designed to bring this brief but classic work to a larger audience. Written for novices in research, the manual is a discussion of the ways in which variables and hypotheses appear in research, the functions they serve, and common problems that researchers have with them. It introduces distinctions and rules and procedures for unraveling variables, examining relationships between them, and analyzing hypotheses. The manual contains five chapters. Chapter 1 explains that the hypothesis, in its elementary form, consists of two variables and a specification of the relationship that one expects to hold between them. Chapter 2 introduces the essence of variables using three general terms--objects, properties of objects, and values of a property--and the two modes of variation--kind and degree. Chapter 3 ventures into the subject of relationships between variables. Chapter 4 delves into the "anatomy of the hypothesis" and discusses the unit of analysis, the null hypothesis, and how to locate and dissect hypotheses in published studies. Finally, the last chapter concerns the two major classes of "diseases" that prevent hypotheses from growing into proper form: those that afflict variables and those that attack specifications of relationships. (MLF)