Decision models

Questions related to decision models could include the following:

• What are the objectives and requirements of the decision makers and thus of the geodesign study?

• What do the decision makers need to know in order to implement changes?

• What are the relative levels of importance of their requirements?

• What are their evaluations based on? Are they scientific evaluations, cultural norms, and/or legal standards?

• Are there any binding constraints on possible outcomes of the geodesign study

• Are there issues of public communication or of visualization?

Impact models

Impact model-related questions include the following:

• Which impact models are needed by the decision model to assess and compare potential changes?

• Which impacts are not part of the decision models but should be considered nevertheless?

• What, how much, where, when, and to whom are the impacts seen as “good” vs. “bad”?

• How precise must the impact assessments be?

Most geodesign studies will be required by law to complete an environmental impact statement and review process in an early stage toward implementation. An environmental impact statement (EIS) identifies the environmental consequences of proposed major changes and developments to the geographic context.It compares these with existing conditions, as well as with projected change withoutthe proposed actions. The requirements of this process will also add models and their specifications to a geodesign study. National, regional, and local governments are likely to have laws and regulations that require specific impact-related studies to accompany any major proposed action.

Change models

Each of these eight change models, plus mixed examples, represents a different strategy for approaching and organizing the design and/or simulation of change. The names of each of these change model strategies reflect their primary approach or characteristic. All eight support the use of scenarios, recognizing that there are an infinite number of future options. The way that the change model is organized and started is crucial and should be preplanned in this second iteration of the framework.

Change model-related questions include the following:

• What are the assumptions for change?

• What are the requirements?

• Who defines the scenarios for change? How?

• Which scenarios are selected? Toward which time horizon(s)? At what scale(s)? How shall change be visualized and communicated?

• Which change models, or way(s) of designing, are most appropriate for this geodesign study?

Selecting among change model approaches

The most important consideration in selecting an approach to design is how certain or uncertain the collaborators in geodesign are about the decision model and its related assumptions and requirements. Anticipatory, participatory, sequential, and optimized change methods all assume (relative) certainty on the part of the geodesign team. In contrast, the combinatorial and constraining approaches assume uncertainty and therefore include the need to systematically explore component options of the assumptions and requirements before integration and commitment. The rule-based, optimized, and agent-based methods presume uncertainty in the assumptions and the final design outcome, but certainty with regards to the rules-of-the-game and how changes occur “in the real world.” Thus these change models are frequently used for testing the sensitivity of the outcome to the parameters of that uncertainty, or when there are several scenarios for change.