The measurement of a product's objective and subjective characteristics, the determination of its image attributes and the segmentation of the consumer population in terms of their product- related expectancies are three steps central to the development of a marketing strategy for a new product. The elaboration of product profile and marketing objectives, the actual product development and the eventual improvements and repositionings of the product during its active life all require that decisions be made that are coherent with the product's real characteristics, its image and its clientele. One's product can rarely be the best in every respect, and it is even less likely to be perceived as being so, or to succeed equally well among all segments of the given market population. After clearly defining the relevant conceptual terms (importance, attribute, choice), the authors discuss the strengths and weaknesses of the most frequently used methods of measuring attributes importance , qualitative methods, direct questioning in its various forms, the method "Duale", methods based on information seeking (protocols), conjoint measurement, methods based on utility theory, regression techniques and linear programming. They then present a new technique for measuring the importance of subjective attributes. Specific image items are first grouped into image dimensions, or attributes, the correlations between these attributes and buying intention then serving as a measure of the attributes' utility. These utilities can be used to segment the consumer population into subgroups that differ widely in terms of their product-related expectancies and buying intentions. Using an underlying compensatory model, the authors are able to determine the relative roles played by perceptions and utilities in determining brand choice. The approach is first presented with respect to automobile research ; in fact, it was first developed in 1982 in order to define the marketing objectives for the Peugeot 405. An example of an application to consumer goods is also presented.