Clark Aldrich's 6 elements of Simulations

http://www.learningcircuits.org/NR/rdonlyres/F2ED000A-7A59-4108-A6CB-1BE4F4CC1CA5/4719/clark_e2.pdf

Three "content" criteria:
- linear,
- systems, and
- cyclical


Three "Delivery" criteria :
- simulation,
- game, and
- pedagogy