Rieber (2005) talks about two main cognitive theories that relate to the use of games, simulations and microworlds in education. The first is dual-coding theory and the second is mental models. Mental models is the theory that I am interested at the moment because M. David Merrill, who I now work closely with at BYU-Hawaii also talks about this in his work.
Mental models are a personal theory of some domain. They are our conception of what a domain is like including what we think are the rules the domain must follow and how we can manipulate these. Rieber (2005) mentions that a mental model is believed to be loosely organized and subject to continual refinement.
I think that an important distinction in the use of mental models is how much or how little of a student's current mental model we find out about and use when we teach. Merrill (2002) would call this the activation principle in his first principles which states:
Learning is promoted when learners activate relevant cognitive structures by being directed to recall, describe or demonstrate relevant prior knowledge or experience.
Merrill indicates that Mental models will not develop well if the learner is not provided with the appropriate guidance, practice and demonstration. I believe activation to be the most important of the first principles besides the task-centered principle because students need to place information into their own mental models for it to create lasting effects on their learning. Integration depends on it, and Application and Demonstration support it.
But I don't think that learners are limited in activating relevant cognitive structures to recalling, describing or demonstrating. When students work with a microworld, they can activate their mental model without doing any of these.
In Microworlds, the user can change a variable and see how the domain reacts. The variable that the user changes is an item in their own mental model that they want to test out. It is not something that their teacher thinks is in the student's mental model, nor is it something that is in a fellow student's mental model. The student herself tests something she wants to know to determine if her mental model is correct. When something unexpected happens, then the student finds out what the discrepancy is and quickly tunes her mental model to fit. this is a very individual and personal process that takes into account many of the differentiating characteristics that students have with regard to learning.
So this is activation without requiring any of the students to recall, demonstrate or describe what they already know. Perhaps the best verb for this type of activation is testing.
Merrill, M. D. (2002). First Principles of Instruction. Educational Technology Research and Development, 50, 43.
Rieber, L. P. (2005). Multimedia Learning in Games, Simulations, and Microworlds. In The Cambridge Handbook of Multimedia Learning. Cambridge, U.K. ; New York: Cambridge University Press.