Chapters * Title * Contents * Introduction * Place * System * Design * Using * Future * Bibliography
Sections
* Place * Constructionist * Evocative * Crystallizing * MediaFusion * Organizing * Why * Glass * Multiplayer * Reflection * MUD
Glass Box Modeling
"When policymakers depend on simulations, they cede power to those who define the models. Washington is already Sim city."
(Starr, 1994)
A simulation that displays its behavior, but not the model that produces that behavior, makes it difficult for a player to see
connections between model and behavior. Will Wright has said that he learned far more building the popular game SimCity than
anyone will ever learn playing it. Design is a particularly powerful learning experience because of the way that experience and
reflection are interwoven. Black box simulations such as SimCity are the norm not because their creators don't want users to
have a more constructive role, but because current design knowledge doesn't extend far enough to provide one. To escape the
black-box problem, MarketPlace uses the tactic of making its simulations multiplayer.
Through a few simple rules which can be explained to players within a few hours (by having them play with the system),
MarketPlace supports exploration of classical market situations with perfect information, no externalities, and diminishing
returns. However, MarketPlace also provides a place to explore markets functioning far from optimality--driven there by
monopoly power, information gaps or positive feedback loops.
MarketPlace underwent a number of trials, with participants of varied backgrounds. As the players increased the sophistication
with which they played, they enriched the way they thought about market phenomenon--and the variety of market phenomena
demonstrated by the simulation.
It's especially important for simulations that purport to model social systems to be open to criticism. MarketPlace attempts to
support players in their critical stance in two ways. Firstly, MarketPlace's transparency helps users feel "qualified" to
criticize the system. The rules are simple enough that users can (and do) suggest alternatives. (Ideally, of course, they could
then try out their alternate versions.) Secondly, players in MarketPlace provide almost all the agency demonstrated in the
game. There aren't hidden computer "players" making decisions for opaque reasons. Things happen because a real person does
something--a decision that can be questioned.
Greg Kimberly/gregkimb@gak.com