fred kerlinger defines theory as "a set of interrelated constructs (concepts) , definitions , and propositions that present a systematic view of phenomena by specifying relations among variables with the purpose of explaining and predicting phenomena. " daniel griffiths includes many of the same ideas in his discussion of theory. he adds that a theory is a deductively connected set of empirical laws and that all statements in a theory are generalizations that explain the empirical laws and unify the areas of subject matter.