Chapters * Title * Contents * Introduction * Place * System * Design * Using * Future * Bibliography
Sections
* Using * Composite_Story * Behavior * Supply_and_Demand * Trade * Central * Externalities * Chicken * Monopolies * Geography * Money
A Composite Picture of a Game
What happened during MarketPlace games? The following paints a composite picture of what went on in the games of the pilot
study. The pilot study games were conducted in an electronic classroom at MIT. Earlier tests had shown that it was very
important to have all the participants in the same room, especially during the critical introductory phase. Students could then
jump directly into using the system, calling upon me or another player when they didn't understand something.
The interface to most of the system was easily grasped and used. During the practice game, students were quickly able to use
the Map window buttons to build factories, the various status displays to see how their status compared to that of their fellow
players, and the Message window to send messages. They would experiment with building various arrangements of
factories--looking at the graphs in the Production Report window to see how each performed. Most students would quickly come to
the conclusion that a clustered set of similar factories was the highest performing arrangement. However, that arrangement left
them in the uncomfortable position of being completely dependent upon their suppliers for production inputs.
Some players had a difficult time buying and selling their commodities through the auction window. Auctions in MarketPlace are
timed, and many students felt pressured by the speed of the auctions when they first started playing. Some students therefore
decided to try to be at least somewhat self-sufficient, producing two or even three commodities.
We then started the "real" game. The first few turns were dominated by considerations of factory siting and configuration.
Students jockeyed for position, generally trying to cluster their factories while avoiding collisions with other players. When
two students claimed the same square, one of them (often the second player) would usually back off. Once, however, the number
of empty squares dwindled, collisions became more frequent. Rather than make the usual four claims on four different plots,
players sometimes used multiple moves to claim one particularly valuable contested square (increasing their chance of winning
it.)
As the map filled up, players paid more attention to trying to produce the most valuable commodities. Players who specialized
in a given commodity, of course, dominated production of it. They produced large surpluses of their commodity and often managed
to sell it for more than they were paying for their production inputs. Given the cyclic nature of MarketPlace commodity
production (to make one food you need two energy and one machinery, and so on), however, shortages in one commodity could
spread to another.
With the inexperienced players of the pilot study, these shortages tended to spiral out of control. As players shifted
production in pursuit of rare commodities their production fell since they could generally only shift half their factories per
turn (and they sometimes miscalculated the inputs the new configuration would require.) The initial supply of commodities
helped the colony make it through the first couple of turns, but by turn four things were usually falling apart. (These
inexperienced players were often fixated on their relative scores, however, and often didn't notice that the colony as a whole
was in trouble.)
The arrival of turn four in MarketPlace marks the arrival of polluting factories. Configuring your factories to pollute drops
their input requirements by one third (you can produce food with just one energy and machinery unit) at the cost of damaging
randomly selected plots. With the colony short of inputs, one or more players would usually reconfigure their factories to
pollute. While they might experience an increase in production as a result, the increase was never enough to pull the colony
back from the brink. As the session time scheduled for playing the game elapsed (or a client Mac crashed), it was obvious to
everyone that the colony was in trouble. It was then time to discuss what had occurred.
Greg Kimberly/gregkimb@gak.com