In the present work, a new approach to construction of single‐valued measures for evaluation of search results is considered in detail. This approach is based first on the formation of certain vectors, and second on the use of functions allowing the evaluation of their closeness. Realization of this approach leads to construction of new, as well as widely‐known, single‐valued measures. A series of constructed measures has a property important in practice, leading to the creation of a mechanism which would allow the selection of the best search method (from a set of available methods) for every query. In this article, a general statement of this property, called the order preservation property, is given, and all considered single‐valued measures are analyzed for the existence of this property. Finally, problems of the legitimacy of the use of single‐valued measures in various specific situations are discussed in the article, and an approach to the solution of these problems is suggested. © 1997 John Wiley & Sons, Inc.