Simon French

Multicriteria Methodology for Decision Aiding

Readers Guide. Foreword to the English-Language Edition. Introductory: How to Aid Whom with What Types of Decision. 1. Decision Problems and Processes. 2. Decision Aiding: Major Actors and the Role of Models. 3. Reference Examples. 4. Phases and Options of an Approach to Decision Aiding (General Ideas of the Methodology). Level I: How to Determine What is Possible and in What Terms to Formulate a Problem. 5. Actions and Decision Aiding. 6. Problematics as Guides in Decision Aiding. Level II: How to Determine Preferences and on What Bases. 7. Preference, Indifference, Incomparability: Binary Relations and Basic Structures. 8. Comparing Actions and Modeling Consequences. 9. Comparing Actions and Developing Criteria. Levels III and IV: How to Proceed from Multiple Criteria to Comprehensive Preferences and Develop Recommendations. 10. Coherent Criterion Family and Decision Aiding in the Description Problematic. 11. Modeling Comprehensive Preferences: Three Operational Approaches for Progressing Beyond the Description Problematic. 12. Specific Difficulties in Choice, Sorting, and Ranking Problematics. Bibliography. Index.

A framework for sensitivity analysis in discrete multi-objective decision-making

Abstract This paper introduces a framework for sensitivity analysis in multi-objective decision-making within a Bayesian context. In designing decision aids, it is essential to check the sensitivity of the conclusions to the data. Data input is constantly revised as decision makers come to understand the implications - and the possible inconsistencies - of their judgements. Sensitivity analysis can focus on those judgemental inputs which are most important in determining choice and, therefore, need to be revised most carefully. After introducing the basic problem, we review some of the previous approaches to sensitivity analysis, which are, by and large, ad hoc specific ‘rules of thumb’, tailored to the particular decision aid being used. Moreover, with few exceptions, they consider sensitivity to one or, at most, two data inputs at a time, the remaining data being taken as fixed. Our aim is to provide a general approach to sensitivity analysis, allowing for simultaneous variation in all the data, benefiting from the recent advances in optimisation theory and the advent of cheap computer power. We introduce several solution concepts, and analytic ways of determining them, which allow us to identify the possible competitors of a current best solution. We analyse, then, distance-based tools for sensitivity analysis, according to some general lines. Finally, we describe some computational experience with two examples and suggest some ways of displaying the information to the decision-maker.

What is a conservative substitution

SummaryIt is commonly recognised that many evolutionary changes of amino acid sequence in proteins are conservative: a substitution of one amino acid residue for another has a far greater chance of being accepted if the two residues are similar in properties. Here we investigate what properties are most important in determining the similarity of two amino acids, from the evolutionary point of view. Our results confirm earlier observations that the hydrophobicity and the molecular bulk of the side chain tend to be conserved. More importantly they also show that evolutionary pressures favour the conservation of secondary structure, and that all these properties can be arranged in a two dimensional diagram in which distances well preserve the observed substitution frequencies between amino acids. These results were obtained by a multi-dimensional scaling technique; and are independent of any prior opinions about conserved properties. Thus, it is demonstrated that all relations of importance to single amino acid substitutions can be represented by a single figure, which is much more comprehensible and useful than the usual tabular representation of substitution frequencies. Such a figure conveniently portrays the “stereochemical code” for conservative substitution.

Design and evaluation of an intelligent decision support system for nuclear emergencies

Intelligent Decision Support Systems (DSSs) use expert systems technology to enhance the capabilities of decision makers (DMs) in understanding a decision problem and selecting a sound alternative. Because of the people-centred focus of such technologies, it is important not only to assess their technical aspects and overall performance but also to seek the views of potential users. This paper draws from the literature to classify methods for assessing intelligent Decision Support Systems and discusses our experiences in developing, operating and evaluating an intelligent decision support system for nuclear emergencies. The system assists decision makers in the formulation and ranking of alternatives and communicates its recommendation in a natural language form. The application highlights insights from the development process and shortcomings of existing assessment methods. Lessons learned from the study, challenges encountered and recommendations for future practices are discussed.

Multi-attribute decision support in the event of a nuclear accident

Retrospective studies of nuclear accidents such as those at Three Mile Island and Chernobyl have emphasized the need for preparing structured decision support methodologies for use in any future emergency. This paper discusses the multi-attribute aspects of such decision support, i.e. methods for supporting decisions when there are several conflicting objectives. Considerable progress has been made in application of these methods over the past 4 or 5 years. In particular, the decision-conferencing format has proved successful in helping senior decision makers understand and deal with the issues that arise in considering long-term countermeasures made. Within the RODOS project, a European initiative to build a decision support system for emergency response, multi-attribute value and utility techniques for short-term and medium-term countermeasures are being developed. However, much remains to be done, particularly in relation to the incorporation of uncertainty when there is a risk of an imminent accident.

Modelling, Making Inferences and Making Decisions: the roles of sensitivity analysis

Sensitivity analysis, robustness studies and uncertainty analyses are key stages in the modelling, inference and evaluation used in operational research, decision analytic and risk management studies. However, sensitivity methods -or others so similar technically that they are difficult to distinguish from sensitivity methods- are used in many different circumstances for many different purposes; and the manner of their use in one context may be inappropriate in another. Thus in this paper, I categorise and explore the use of sensitivity analysis and its parallels, and in doing so I hope to provide a guide and typology to a large growing literature.

e-Participation and Decision Analysis

Decision analytic methods are being increasingly used to help to articulate and structure debate and deliberations among citizens and stakeholders in societal decisions. Methods vary, but, essentially, a public authority or agency, when faced with a significant set of issues, may organise one or more workshops with stakeholders and citizens as participants. Such methods of public engagement and participation are, by and large, conducted face to face. However, the advent of the World Wide Web brings the possibility of conducting citizen and stakeholder interactions in a distributed, possibly asynchronous fashion. In this paper we discuss the challenges that have to be addressed and overcome if such e-participation is to be a valid tool within a modern democracy. The difficulties are many and varied, but the pressures towards e-government, and better regulation in general, mean that such methods will be used in the near future. Thus, we outline a program of research and debate in which we believe that the professional decision analysis community should engage.

Explaining and justifying the advice of a decision support system: a natural language generation approach

Abstract This paper describes a method for generating explanations in decision analytic contexts. Unlike other approaches, we use natural language generation techniques. The novelty of the work stems from the development of a library of text plans that structure the explanation messages conveyed. This makes our approach generic and easily adjusted to different contexts. In order to demonstrate the applicability of the method, we have developed a natural language generator that explains and justifies the advice of a decision support system for nuclear emergencies. The generator outputs two reports: a comparative report that explains the rationale behind the ranking of the alternatives and a sensitivity analysis report that gives an overall assessment of the decision model and describes the effect of varying a decision parameter.

Web-enabled strategic GDSS, e-democracy and Arrow's theorem: A Bayesian perspective

Web-technologies bring the possibility of supporting geographically and temporally dispersed decision making. However, although technically feasible, it is not clear that there are valid methodologies for the use of web-based group decision support (wGDSS). Many approaches to decision support are driven by the perspective of a single decision maker. Yet there are many reasons to expect that the extension of individualistic theories to a group context will be fraught with difficulty. This paper explores these issues and considers the way forward for the design and use of wGDSS and for a more substantive approach to participative e-democracy.

RODOS: Decision Support for Nuclear Emergencies

In the thirteen years that have elapsed since the Chernobyl accident, many studies and developments have been made with the aim of improving our response to any future accident. One project has been the development of a decision support system to aid emergency management. rodos, a Real time online Decision support system for nuclear emergency management, has been built by a consortium of many institutes across Europe and the cis. As it approaches (standby!) operational use, we face the task of tailoring the output to meet the specific needs of users and simultaneously opening up their minds to full potential of a modern decision support system (dss). This paper reports a number of investigations into the decision support needs of the competent national safety authorities and reflects on the implications of rodos for the emergency management process.