Abstract

This article describes a study on capacity limitations that affect the construction of spatial mental models. A process model is presented, according to which the construction of a mental model in Ehrlich and Johnson-Laird's (1982) spatial descriptions task places a workload of six information chunks for continuous and semi-continuous descriptions, and seven chunks for discontinuous descriptions. Participants (48 undergraduate students) performed the spatial descriptions task and the figural intersections test (FIT), which yields a capacity score. The pattern of errors and sentence reading times in the spatial descriptions task confirmed that participants were using mental models. The FIT score was positively correlated with accuracy in the spatial descriptions task. Prediction analysis of cross-classification tables showed that, for successful performance in continuous and semi-continuous descriptions, a FIT score of 6 was necessary, and a score of 7 in discontinuous descriptions. These results are in agreement with theoretical predictions. The issue of integrating mental models theory with analyses of capacity limitations in performance is discussed.