Ralph L. Keeney

Multiplicative Utility Functions

This paper presents sufficient conditions for a multiattribute utility function to be either multiplicative or additive. The number of requisite assumptions to imply the main result is equal to the number of attributes. Because the assumptions involve only trade-offs between two attributes at a time or lotteries over one attribute, it is reasonable to expect that decision makers can ascertain whether these assumptions are appropriate for their specific problems. Procedures are given for verifying the assumptions and assessing the resulting utility functions. The paper concludes with a sketch of a recent application of the results to a six-attribute problem relating to the development of Mexico Citys airport facilities.

Feature Article—Decision Analysis: An Overview

This article, written for the nondecision analyst, describes what decision analysis is, what it can and cannot do, why one should care to do this, and how one does it. To accomplish these purposes, it is necessary first to describe the decision environment. The article also presents an overview of decision analysis and provides additional sources for its foundations, procedures, history, and applications.

Eliciting probabilities from experts in complex technical problems

A formal elicitation process is summarized to obtain probabilities from experts in a large-scale study involving nuclear safety. A first expert elicitation, using primarily in-house experts and staff members of the project team was strongly criticized in peer review. Subsequently, many changes in the process and procedures were made including training experts in making probability judgments, providing assistance in decomposing judgments, formally eliciting probabilities in individual sessions, and documenting the results. Approximately 1000 probability distributions were assessed from about 40 experts from universities, consulting firms, and national laboratories. This second elicitation was much better received by peer review. Based on this experience, a comprehensive process to elicit probability judgments is outlined in detail. >

Conflicting objectives in decisions

This book deals with quantitative approaches in making decisions when conflicting objectives are present. This problem is central to many applications of decision analysis, policy analysis, operational research, etc. in a wide range of fields, for example, business, economics, engineering, psychology, and planning. The book surveys different approaches to the same problem area and each approach is discussed in considerable detail so that the coverage of the book is both broad and deep. The problem of conflicting objectives is of paramount importance, both in planned and market economies, and this book represents a cross-cultural mixture of approaches from many countries to the same class of problem.

Value-focused thinking: Identifying decision opportunities and creating alternatives

Conventional approaches to decisionmaking focus on alternatives. However, alternatives are relevant only because they are means to achieve values. Therefore, thinking about decision situations should begin with values. Value-focused thinking describes and illustrates concepts and procedures for creating better alternatives for your decision problems, identifying decision opportunities more appealing than the decision problems that confront you, and articulating and using your fundamental values to guide and integrate your decisionmaking activities. The ideas are relevant to your personal decisions and to the decision situations of organizations. The concepts and procedures are illustrated by an application at British Columbia Hydro and short descriptions of several other applications.

Selecting Attributes to Measure the Achievement of Objectives

The foundation for any decision is a clear statement of objectives. Attributes clarify the meaning of each objective and are required to measure the consequences of different alternatives. Unfortunately, insufficient thought typically is given to the choice of attributes. This paper addresses this problem by presenting theory and guidelines for identifying appropriate attributes. We define five desirable properties of attributes: they should be unambiguous, comprehensive, direct, operational, and understandable. Each of these properties is discussed and illustrated with examples, including several cases in which one or more of the desirable properties are not met. We also present a decision model for selecting among the different types of natural, proxy, and constructed attributes.

A Market Share Theorem

Many marketing models use variants of the relationship: Market share equals marketing effort divided by total marketing effort. Replacing marketing effort with its resulting “attraction,” the relationship is derived from the assumptions: (1) attraction is nonnegative, (2) equal attractions imply equal shares, and (3) a seller’s share is affected the same if the attraction of any other seller increases a fixed amount.

Common Mistakes in Making Value Trade-Offs

Value trade-offs define how much must be gained in the achievement of one objective to compensate for a lesser achievement on a different objective. Value trade-offs that adequately express a decision makers values are essential both for good decision making in multiple-objective contexts and for insightful analyses of multiple-objective decisions. This paper identifies and illustrates 12 important mistakes frequently made that limit ones ability to determine useful value trade-offs. It then suggests how to avoid making these mistakes. The intent is to provide practical advice for making good value trade-offs, and hence, better decisions.

Structuring Objectives for Problems of Public Interest

The analysis of problems of public interest requires a broad range of objectives. This paper outlines and illustrates a procedure to constructively involve stakeholders in the process of identifying these objectives. The illustration concerns the evaluation of alternatives to ship spent nuclear fuel from power plants to a repository. Objectives were developed from group discussions with individuals in the nuclear industry, in state governments, and in environmental and public interest organizations. Using guidelines outlined in the paper, hierarchies of objectives were structured to represent each of these stakeholders. From these, a combined hierarchy was structured that addressed health and safety; economics; equity; environmental, social, and political impacts; flexibility; and scheduling.

Equity and Public Risk

Possible fatalities to members of the public are defined in this paper as public risk. Given other things are equal, such as the benefits to individuals in society, there may be a preference for an equitable balancing of individual risks. This concept of equity is defined and it is shown that any utility function over number of fatalities which exhibits this equity condition must be risk prone. Commonly used indicators, such as the average risk per person and the expected number of fatalities, do not promote equity. An attitude of aversion toward catastrophes is defined and shown to conflict with risk equity.