Does marketing contain a set of well-defined principles that can help managers to make better decisions? If so, are these principles communicated effectively? We assumed that the answer to the first question was ”yes,” and undertook a project to see how much progress has been made in developing marketing principles. Our goal was to develop an inventory of marketing principles and to see how this inventory changed over time. But in trying to develop this inventory, we were confronted by the second question, that is, the communication of knowledge. Thus, we sought to develop an inventory of the principles that are actually being communicated. As a working definition, we defined principles as normative statements that specify a condition followed by a suggested action. That is, marketing principles should provide operational guidelines, telling managers how to act in a given type of situation. An example of a principle is that the illustration in a print ad should be placed above the copy. Principles should help marketing managers to make better decisions because they incorporate marketing knowledge derived through previous research and experience. A well-developed set of principles can act as a basis for an expert system. For example, Burke et al. (1990) developed an expert system in advertising based heavily upon the principles presented in the advertising textbook by Rossiter and Percy (1987).

Well-supported principles of marketing should be of interest to marketing practitioners. Those who make marketing decisions might like to know what principles can help them make better decisions. Such principles, for example, might show the conditions under which an increase in prices would improve profitability. In many disciplines, basic principles seem to be transmitted through introductory textbooks. We wondered whether marketing was similar in this respect. The titles