The various parties in decision analysis of a public policy
issue have
different reality judgments
different value judgments
which imply
different decision tree structures
different sets of probabilities
different preference and utility functions
These differences are identified and explained by the decision analyst to enhance mutual understanding among the interested parties.
VOSDA is not intended to force consensus, but it
includes an interpersonal communication component
which uses
threat-reduction rhetoric
to encourage
conflict resolution and facilitate compromise
through the
political process.
"The elaboration of the reality system and the value system proceed
together.
Facts are applicable only to some standard of value;
Values are applicable only to some configuration of fact. " --Geoffrey
Vickers=
1) clarify the problem: Situation Analysis Maps
2) identify alternative actions and possible consequences: Decision Trees
3) determine & describe preferred policies of individual
participants: Cost models and Social Models
1) Discuss the issue and problem with each person or group individually
in order to obtain their
perceptions of the problem.
2) Prepare a descriptive summary of each person's or group's analysis
("perceptions") of the problem,
and have those persons
and groups revise and edit these descriptions.
3) Circulate these analyses of the problem, as well as a composite
of the analyses, among every person and group involved in the issue.
We suggest that these
descriptions be circulated graphically in the form of "situation analysis
maps."
1) Meet with individuals & groups and talk them through the construction
of a decision tree from the basic policy alternative (e.g., whether or
not to install a solid waste shredder at the city landfill).
The decision analyst uses an individual's situation analysis map
as a guide to enable the individual to suggest his or her individual decision
tree.
2) Design a composite decision tree from the individual decision
trees, and
check with individuals and groups on the forms of their own decision
trees before these are circulated.
3) Circulate these individual decision trees among every person or
group involved in the issue,
and circulate the composite decision tree as well.
Shade individual trees on the composite tree so that everyone can
easily compare his or her tree with everyone else's as well as with the
composite tree.
1) Prepare costs and social effects models based on all available information and identified in the composite situation analysis map and decision tree.
2) Meet with individuals and groups to have them assign probabilities
and preferences to each effect for each option they consider viable.
They also should establish an indifference ratio to integrate costs
and social effects.
3) Calculate each individual's priority rankings of their options,
by cost model
by social effects model
by composite (tradeoff) model
and meet with each person to discuss their individual decision analysis
results.
Encourage persons to revise their judgments of probabilities and
preferences so that they are comfortable with their individual decision
analysis results.
4) Circulate the set of individual decision analysis results,
including cost X social graphs
along with the decision analyst's description of similarities, differences,
uncertainties, sensitivities among results & models.