Mental models of mechanical systems: individual differences in qualitative and quantitative reasoning.

@article{Hegarty1988MentalMO,
  title={Mental models of mechanical systems: individual differences in qualitative and quantitative reasoning.},
  author={Mary Hegarty and Marcel Adam Just and I R Morrison},
  journal={Cognitive psychology},
  year={1988},
  volume={20 2},
  pages={191-236}
}