The notion of generality, or broad application, is important. Thus, theories are by their nature abstract and not content- or topic-specific. Even though various theoretical models of health behavior may reflect the same general ideas, each theory employs a unique vocabulary to articulate the specific factors considered to be important. Theories vary in the extent to which they have been conceptually developed and empirically tested; however, “testability” is an important feature of a theory. As Stephen Turner has noted in his chapter on “Theory Development,” social science theories are better understood as models that work in a limited range of settings, rather than laws of science which hold and apply universally.