JOURNAL OF MULTI-CRITERIA DECISION ANALYSIS

J. Multi-Crit. Decis. Anal. 14: 191–193 (2006)

Published online in Wiley InterScience

(www.interscience.wiley.com) DOI: 10.1002/mcda.411

Re£ections on Howard Rai¡a’s ‘Preferences for Multi-AttributedAlternatives’

SIMONFRENCH*Manchester Business School, Manchester, UK

Reading Howard Raiffa’s seminal paper, RM-5868, brought on waves of nostalgia, despite thefact that I was reading it in 2006 for the first time.The quarter century from 1950 to 1975 was inmany ways the heyday of decision theory. All thekey ideas and research imperatives were laid downthen. Well perhaps not all: but the subject wasdefined and its foundations laid. But the nostalgiawas not for the early years of decision theory: itwas for an academic world in which ideas wereoffered and debated with a zeal and openness thatseems absent today. Perhaps if I am reading toomuch into the feel of a mimeographed workingpaper; but here is a document that literally shapeda vast literature. Were such a working paperproduced today, the research assessment exercisesin many countries, the UK in particular, woulddeclare it a valueless piece of unpublished work.Many institutes would discourage their membersfrom circulating such a draft until it had beensubmitted, lest intellectual property rights werelost. Many journals would declare it too long forpublication and those that would consider it wouldprobably ask that its style were less reflective and itfocused on the completed aspects of its contents.At our modern overcrowded conferences in a 20–30min paper, only a fraction of the ideas could bepresented. OK, I am overstating things, but I amconcerned that academic research is becomingcommoditized, neatly packaged and regulated bysimplistic assessments, so much so that we arelosing the idea of debate, of risking exposing half-formed thoughts for discussion and perhaps forothers to take forward. Enough! I am ranting; letme turn to the substance of this truly great paper.

So many of the ideas that permeate decisiontheory and the modern practice of decision

analysis are present here. The one I use mostcommonly is probably the simplest, namely, therepresentation of the important characteristics ofthe possible outcomes of a decision as an attributehierarchy. I find time and again the effectiveness ofsuch representations in focusing managementgroups’ attention on the issues that matter tothem, enabling them to structure deliberationsefficiently. Developing attribute hierarchies withgroups has time and again paid dividends inhelping them identify and express what they aretruly seeking to achieve. They are the mechanismsby which the value-focusing thinking approach isarticulated (Keeney, 1992). Although they are theinfrastructure on which quantitative multi-attri-bute value and utility (MAV/U) analyses are built,in many ways I find the softer uses of attributehierarchies the more important. For instance,when conducting a decision analysis, I will usuallyhave a flipchart with the hierarchy fairly centrallyin the room as a subliminal reminder of what thedecision makers are trying to achieve. Software forMAV/U analyses also tends to incorporate theattribute tree into their main screen with much thesame effect. Discussions of soft OR or problem-structuring methods (Franco et al., 2006; Mingersand Rosenhead, 2004; Pidd, 2004; Rosenhead andMingers, 2001) seldom, it seems to me, accord thedevelopment of attribute hierarchies the impor-tance that they deserve. Yet, to develop a richpicture diagram or systems representation of a setof issues one needs clarity on the objectives inorder to filter out the irrelevant. Thus, I foundHoward Raiffa’s early discussion of methodologiesfor constructing attribute trees fascinating. Heremarks on the influence of the work of Miller,and Mannheim and Hall, but his argumentsclearly take the ideas forward.

One of the reasons I find attribute trees so usefulis that their early construction in an analysismakes the decision-makers agree on their objecti-ves}or equally helpfully, surfaces their disagree-

*Correspondence to: Manchester Business School,Booth Street West, Manchester, M15 6PB, UK. E-mail:simon.french@mbs.ac.uk

Copyright # 2007 John Wiley & Sons, Ltd.

ments. So I was somewhat disappointed to find solittle discussion of group decision making issues.Given that his work on group decisions andnegotiations has extended over the best part ofhalf a century (Luce and Raiffa, 1957; Raiffa,1982; Raiffa et al., 2002), I had hoped to see somediscussion that was formative in his later work; buthe dismisses group aspects here (p. 3) by assuminga single decision maker. That said, there are somepreliminary ideas that relate to the concept of asupra decision maker (p. 7). In many ways,developments in the 1980s and 1990s ignored thisconcept. I and others argued strongly (French,1986), that introducing a hypothetical supradecision maker did not help resolve groupdisagreements because the group would need toagree on the characteristics of this hypotheticalentity so its introduction merely moved the issue ofgaining group agreement one level higher. How-ever, recently I have become aware that theunderlying ideas may gain expression in somedevelopments of deliberative democracy and pub-lic participation (French et al., 2006; Renn et al.,1995; Rowe and Frewer, 2000). As our democraticprocesses move to involve citizens in the societaldecisions that particularly affect them, we areexploring ways in which their preferences can bedrawn into the decision analyses. For manyreasons, including especially concerns that thecitizens who become involved in these participa-tory processes may not be representative of societyas a whole, the authority for actually taking thedecision is often left to some regulatory bodywhich uses the participatory process as ‘advisory’rather than providing a legally binding vote ofsome kind. Regarding such regulatory bodies assupra decision makers may bring a useful perspec-tive on designing the participatory process. Hence,it is interesting to see the examples in this RANDreport revolve around decisions taken by aregulator.

Surprisingly there is a notable absence of a keyidea of decision analysis, not just in this paperbut}dare I be critical?}in the vast majority ofHoward Raiffa’s writings. The importance ofsensitivity analysis seems to me to be overlooked(French, 1995; Rios Insua and French, 1991).Sensitivity analysis enters a decision analysis inmany ways (French, 2003). In the context ofMAV/U modelling it can help to support theelicitation of judgemental inputs to an analysis, toexplore and build consensus and, above all, tobuild understanding: see also Larry Phillips’ idea

of requisite decision modelling (Phillips, 1984). Yetthere is no discussion of sensitivity analysis here. Iwonder if this omission is the sign of that early erain the 1950s and 1960s in which the axiomaticfoundations of Bayesian statistics and decisiontheory were laid; another area in which HowardRaiffa contributed significantly (Raiffa, 1968;Raiffa and Schlaiffer, 1961). My reading of thatperiod is that it was believed that real decisionmakers could achieve the absolute clarity of self-introspection assumed in the model rationaleconomic man. Sure, our instinctive behaviourwas subject to many of the heuristics and biases,later researched in depth by Kahneman, Tverskyand their co-workers (see, e.g. Kahnemanand Tversky, 1974, 2000), but with sufficientthought we could know our beliefs and preferencesabsolutely. Thus, the debate was betweennormative and descriptive}should versus do}-perspectives on decision-making, and since nor-mative ideals underpinned decision analyses,the numbers representing beliefs and preferenceswould be accurate. There would be no need forsensitivity analysis. It was not until thedebate recognized a trichotomy, normative, de-scriptive and prescriptive, that the needand the roles for sensitivity analysis really werediscussed. Prescriptive perspectives on decisionanalysis recognizes that its purpose is to helpreal decision makers towards the ideals of norma-tive models, mindful of their cognitive limitations,among many of which is their inability tospecify probabilities, values, utilities, weightsto unlimited accuracy. It is, of course, completelyunsurprising that Howard Raiffa wasamong the first to recognize the distinctivenature of the prescriptive perspective (Bell et al.,1988).

I have been silent on the quantitative aspects ofthe report. Many of the ideas here on indepen-dence concepts and the structuring of MAV/Ufunctions played out in the subsequent years,particularly in the seminal book with RalphKeeney (Keeney and Raiffa, 1976). I shall notexplore those here. What I would remark onis that this paper marks a change in approachand style of decision theoretical proofs andmodels. Generalizing very broadly}there areclear exceptions}most of the earlier axiomatiza-tions of subjective expected utility models hadtended to lead to non-constructive proofsof existence. Mathematical derivations wereelegant with the representations popping out at

S. FRENCH192

Copyright # 2007 John Wiley & Sons, Ltd. J. Multi-Crit. Decis. Anal. 14: 191–193 (2006)

DOI: 10.1002/mcda

the end. Howard Raiffa’s style has always tendedto be different. Axioms are stated to enable thenecessary assumptions to be made in constructinga value or utility representation. The resultingproof has always seemed to me to the morepersuasive, if less elegant mathematically. It alsoleads to a theory that develops naturally intodecision-analytic methodologies.

Reading this report nearly 40 years after it waswritten has been a joy. It has given me pause forthought in so many ways. It was and is a seminalwork. Howard, thank you.

REFERENCES

Bell DE, Raiffa H, Tversky A. 1988. Decision Making.Cambridge University Press: Cambridge.

Franco A, Shaw D, Westcombe M (eds). 2006. Specialissue: problem structuring methods. Journal of theOperational Research Society 57(7): 757–878.

French S. 1986. Decision Theory: An Introduction tothe Mathematics of Rationality. Ellis Horwood:Chichester.

French S. 1995. Uncertainty and imprecision: modellingand analysis. Journal of the Operational ResearchSociety 46: 70–79.

French S. 2003. Modelling, making inferences andmaking decisions: the roles of sensitivity analysis.TOP 11(2): 229–252.

French S, Rios Insua D, Ruggeri F. 2006. E-participa-tion and decision analysis. Decision Analysis (underrevision).

Kahneman D, Tversky A. 1974. Judgement underuncertainty: heuristics and biases. Science 185: 1124–1131.

Kahneman D, Tversky A (eds). 2000. Choices, Valuesand Frames. Cambridge University Press: Cambridge.

Keeney RL. 1992. Value-focused Thinking: A Path toCreative Decision Making. Harvard University Press:Cambridge, MA.

Keeney RL, Raiffa H. 1976. Decisions with MultipleObjectives: Preferences and Value Trade-offs. Wiley:New York.

Luce RD, Raiffa H. 1957. Games and Decisions. Wiley:New York.

Mingers J, Rosenhead J. 2004. Problem structuringmethods in action. European Journal of OperationalResearch 152: 530–554.

Phillips LD. 1984. A theory of requisite decision models.Acta Psychologica 56: 29–48.

Pidd M. (ed.). 2004. Systems Modelling: Theory andPractice. Wiley: Chichester.

Raiffa H. 1968. Decision Analysis: Introductory Lectureson Choice under Uncertainty. Addison-Wesley: Read-ing, MA.

Raiffa H. 1982. The Art and Science of Negotiation: Howto Resolve Conflicts and get the Best out of Bargaining.Belknap Press, Harvard University: Cambridge, MA.

Raiffa H, Richardson J, Metcalfe D. 2002. NegotiationAnalysis: the Science and Art of Collaborative DecisionMaking. Harvard University Press: Cambridge, MA.

Raiffa H, Schlaiffer R. 1961. Applied Statistical DecisionTheory. Harvard University.

Renn O, Webler T, Wiedermann P. (eds). 1995. Fairnessand Competence in Citizen Participation: EvaluatingModels and Environmental Discourse. Kluwer:Dordrecht.

Rios Insua D, French S. 1991. A framework forsensitivity analysis in discrete multi-objective decisionmaking. European Journal of Operational Research 54:176–190.

Rosenhead J, Mingers J. (eds). 2001. Rational Analysisfor a Problematic World Revisited. Wiley: Chichester.

Rowe G, Frewer LJ. 2000. Public participation methods:a framework for evaluation. Science Technology andHuman Values 25(1): 3–29.

REFLECTIONS ON HOWARD RAIFFA’S ‘PREFERENCES FOR MULTI-ATTRIBUTED ALTERNATIVES’ 193

Copyright # 2007 John Wiley & Sons, Ltd. J. Multi-Crit. Decis. Anal. 14: 191–193 (2006)

DOI: 10.1002/mcda