Learning to understand the balance beam

Twenty-two university students who did not initially know the quantitative rule for predicting whether a configuration of weights placed on a balance beam would cause the mean to balance, tip left , or tip right were asked to induce the rule in a training procedure adapted form Siegler (1976). For each of a series of balance beam problems, subjects predicted the action of the beam and explained how they arrived at their prediction. Protocols revealed that although all subjects realized early on that both weight and distance were relevant to their predictions, they used a variety of heuristics prior to inducing the correct quantitative rule. There heuristic included instance-based reasoning, qualitative estimation of istance, and the use of quantitative rules of limited generality. The commohn use of instance-based reasoning suggests that learning to understand the balance beam cannot be described completely in terms of a simple rule acquisition theory. Also, the variability in the use of heuristics across subjects suggests that no simple theory that depicts subjects as linearly progressing through a hierarchy of levels can adquately describe the development of balance understanding.