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North et al. Complex Adaptive Systems Modeling 2013, 1:3
http://www.casmodeling.com/content/1/1/3
Essential agent-based model design questions
Once agent-based modeling has been identified as a candidate methodology for solving
the problem, the following questions can be asked:
What are the modeling question(s)?
Who are the stakeholders?
What outputs are needed?
What input data are available?
What verification and validation (V&V) is needed?
What alternative techniques where tried?
Who are the agents?
What are the agent behaviors?
What is the agent environment?
Each of these questions will be briefly addressed in our next section for our example
CAS.
What Are the Modeling Question(s)? The modeling question is: how does the quality
of ideas change over time in the innovation network?
Who Are the Stakeholders? The stakeholders in this demonstration case are simply
the modelers themselves.
What Outputs Are Needed? The output will be the history of the quality of
innovation. This output will be displayed as a time series chart.
What Input Data Are Available? For this model, the input will be the probability of
developing a new innovation on a given time step.
What V&V is Needed? The V&V step is key. It can be said that V&V turns toys into
tools (North and Macal 2007). V&V is like a properly prepared court case in that modelers select a standard of evidence and then prepare arguments to meet the standard. To
be properly prepared, countervailing facts must also be presented!
There are many sources of potential evidence for the arguments, including by:
Conducting design and code walkthroughs;
Performing unit testing;
Conducting face validity checks;
Docking against other models;
Trying real-world and tricky artificial cases; and
Conducting parameter sweeps and sensitivity analyses.
Simple face validity checks will be used for the innovation model.
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