“…Models may also differ considerably in complexity, and range from very simple straightforward models, e.g., simple Mendelian genetics (Brant, Hooper, & Sugrue, 1991) to very complex models, e.g., the medical simulation HUMAN (Coleman & Randall, 1986) in which 200 variables and parameters can be changed. Also, specific characteristics like the place of variables in the model, or the distance between theoretical and operational variables characterize the conceptual model (Glaser, Schauble, Raghavan, & Zeitz, 1992). In scientific discovery learning the main task of the learner is to infer the characteristics of the model underlying the simulation.…”