Diagnosis—The Handmaiden of Prediction

Marketing literature is full of examples of the hazards of predicting national performance before test marketing. Despite this, many marketing and research practitioners still believe that certain measures of buying appeal can be used well before test market launch to predict national performance. Indeed, some practitioners are so bold as to believe that this is possible even at the very earliest stage-when a new product is merely 'a germ of an idea, a bare concept with none of its ultimate trappings. Admittedly, the issue of national market performance is always with us, and rightly so, from the very inception of an idea. But this goal is not well served by focusing on so-called predictive measures throughout the various testing stages of the product idea. If we are to enhance our prospects for eventual market success, we must instead focus on diagnostic measures during the early stages of product development and testing.