Table 1.

Overview of complexity characteristics of microworlds in general and in C³Fire (cf. Funke, 2001).

Complexity	General	C3Fire examples	Representation in Figure 4
Goals	People try to reach many goals, some of which may be contradictory, and therefore they have to make trade-offs.	Extinguish a forest fire and/or protect houses simultaneously.	Two fires are spreading out. Brown cells are extinguished, black cells are burned down. A house and a school are blocked with fire-breaks (gray cells).
Side-effects	Side effects of a given course of action exist due to coupled processes and force people to choose between many possible courses of action.	If the participant decides to refill his/her water tank on his/her back, he/she is not able to fight a fire during this refill process.	Unit 2, one firefighting unit, stands on the local water tank for refilling its water supply.
Dynamic	Microworlds are dynamic, because “their current state is a function of the history of the interaction between the subject and the system” and “they change, both as a consequence of the subject's actions and autonomously” (Brehmer and Dörner, 1993, p. 173). People have to act in real time and directly influence the system's state even though they do not know exactly when they have to make decisions.	If the participant does nothing, the fire spreads in all directions. If the participant extinguishes burning fields, the fire spreads in the directions where no firefighting occurs. If the wind direction changes, the direction of fire spreading also changes and the participant needs to recognize this for his/her further actions.	Two fires are spreading out into all directions. The fire stops bevor a placed fire-break. The fire spreads out predominantly in a westward direction, because the wind is coming from the East.
Opaque	Opaque means that the people do not have all relevant information. Thus, people have to form hypotheses and test them autonomously during activity.	Restricted visibility field. Not everything within the simulation environment is visible for the participants without exploring the environment. All units see the houses, trees, bushes and so on, but they can only see the fire if they are close to it.	The restricted visibility field is represented by the yellow squares. e.g., unit 5 only sees five burning cells and four non-burning cells and has an intersection of two cells with unit 4. Unit 1 only sees eight burning cells and one burned-out cell and has an intersection of one cell with unit 4.