Thinking and Deciding

346 DECISION ANALYSIS AND VALUES
of psychology might make it harder to get a majority vote for a candidate directed
more at “wisdom and enlightenment” (2C). When I realized this, I also realized that
we had other options for dealing with this problem, such as changing the voting rules
so that the scientific and wisdom parts of the department would have equal say, no
matter how many members each area had. We did not do this, but my realization
illustrates one of the beneficial side effects of this kind of analysis: it leads us to
consider a wider range of possible options, and sometimes one of these will be better
than the options in the range we were considering.
Decision analysts sometimes convince a group of people to use a framework
like this to make a real decision. The process is time consuming, too much for
the purpose at hand. It would require several steps. The initial diagram would be
developed by the analyst after preliminary discussion, then presented to the group
for their criticism. Everyone should agree that it includes all relevant goals, however
important or unimportant they seem to each person. The idea is that people will agree
on this list even if they disagree on the weight that each element should receive. This
process can lead to increased agreement. It can force each member to give some
consideration to goals that are important to others but that she would ignore. She
would ignore them because of her single-minded concentration on only the goals
most important to her. A listing of attributes is this an antidote for single-mindedness.
The next step would be to define each attribute so that it can be measured numerically.
Then the group might be able to agree on the assignment of numbers to each
option (in this case, each field in which the department hire, perhaps) on each attribute.
This can be done by averaging individual estimates. Such agreement is more
likely when people agree on the meaning of the attributes. No agreement about their
importance or weight is needed yet. Finally, each member would assign a weight to
each attribute. An analysis for that member would multiply the weight by the number
assigned to each option on each attribute and add up across the attributes so as
to assign a utility to each option. (Later, I shall give more detailed examples of this
process of multiplying and adding.) At this point, the analyses of individual members
would be aggregated into an overall analysis. This could be done by averaging
the weights assigned to attributes or (equivalently) the utilities assigned to options.
Ordinarily, this would be done in a preliminary way, then discussed by the group,
then done again.
Conjoint measurement
Before returning to multiattribute analysis, I want to step back to examine its theoretical
basis in conjoint measurement. Conjoint measurement is a mathematical idea
that justifies multiattribute analysis and that has also led to another method for utility
assessment, called “conjoint analysis,” which is discussed in Chapter 15.
Conjoint measurement deals with the situation we have been discussing, in which
outcomes can be described in terms of two or more attributes. An “attribute,” in this
case, is a value on a dimension. The price of a given computer, for example, is an