It is appropriate to turn now to what is meant here by theory as that word applies to public administration. At a loose and almost casual level, theory is simply an orientation, framework, technique, or approach. For example, without referring to a particular theory, one might write that there is theory (or there are theories) of life cycles in organizations. Or one might refer to a personal opinion as a theory. Theory is not used here in this relaxed form. Theory, in the more formal meanings of the term, has the following three meanings. First, in the natural and physical sciences, theory means a rigorous testing of predictive theorems or hypotheses using observable and comparable data. These hypotheses, once tested and verified, form the basis of theories, assertions, or representations of reality. Theory in the natural or physical sciences can claim considerable accuracy in representing reality because the classification of order in the physical world is advanced, as are capacities to recognize and measure natural phenomena. Theory, thus derived, often serves as a highly reliable guide for action. In the social world, of which public administration is a part, the problems of recognizing patterns, designing categories, and measuring and comparing phenomena are much greater. Therefore, the aims of theory of theory in public administration are different (and, some would say, lower).