Theories, Use of

A theory is essentially a set of assumptions from which a set of empirical laws (or principles) may be derived. What makes a theory a theory? For a proposal to be a theory, it must be descriptive, analytical, and predictive. To be descriptive, it must point to the phenomenon being described, such as a series of behaviors being described by a leadership theory. Next, it must analyze relevant phenomena. For example, some leadership behavior may be classified as structuring tasks, while others as concern for subordinates' wellbeing. Last, the predictive criterion requires the theory to predict that certain leadership behaviors to be perceived as effective will focus on achieving tasks, while other behavior will be directed at meeting subordinates' emotional needs.

These criteria for theory separate it from models (the Getzels-Guba model) and taxonomies; the former is more descriptive, while the latter is both descriptive and analytic. Models function as metaphors, while taxonomies function as classification devices. Both lack the capacity to predict.

While most Americans separate theory and practice, most scientists perceive their connection. John Dewey's deliberate use of the singular notes his perception of the unity of theory and practice. Further uses of theory include its objectivity, although Thomas Kuhn noted that scientists and the public subscribe to a paradigm until some divergent theory comes along to challenge accepted conventional wisdom. Theory ought to be comprehensive, covering a considerable range of phenomena under its rubric, such as the leadership behavior of a large number of individuals. A theory also should be a guide to new knowledge. Any theory in the behavioral sciences should be a guide to action, as well as a guide to collecting relevant data, such as what the impact on morale will be of the superintendent reducing principals' degree of freedom.

Last, issues of validity and reliability arise. Validity concerns whether we actually are investigating what we think we are investigating. Reliability refers to the issue of whether we can replicate the processes and results achieved in our first attempts. Qualitative studies, many of which deal with cases, focus more on descriptive validity, moving away from dealing with reliability.