Classes in the balance: Latent class analysis and the balance scale task

Latent class analysis (LCA) has been successfully applied to tasks measuring higher cognitive functioning, suggesting the existence of distinct strategies used in such tasks. With LCA it became possible to classify post hoc. This important step forward in modeling and analyzing cognitive strategies is relevant to the overlapping waves model for strategy development [Siegler, R. S. (1996). Emerging minds: The process of change in children’s thinking. New York: Oxford University Press.]. However, so far, developmental trends were not part of the statistical model. Moreover, the theoretical importance of the fact that a few distinct classes were found was weakened because not all these classes represented pure strategies. To address these two issues, we model the development in class membership by incorporating age and working memory as covariates in the LCA model. Previous findings that the classes are well demarcated are replicated. A developmental sequence is supported by a strong effect of age on class membership and a moderate effect of working memory. Classification itself is hardly affected by the covariates: the problem of difficult to characterize classes remains. Nevertheless, classes describe large proportions of children’s responses, classes are robust and fit a developmental trend, and some classes represent mixed rule use. In the discussion, the theoretical status of the overlapping waves model is clarified.