Age-related changes in children's use of external representations.

Abstract

This study explored children's use of external representations. Experiment 1 focused on representatio ns of self: Self-recognition was assessed by a mark test as a function of age (3 vs. 4 years), delay (5 s vs. 3 min), and media (photographs vs. drawings). Four-year-olds outperformed 3-year-olds; children performed better with photographs than drawings; and there was no effect of delay. In Experiment 2, 3- and 4-year-olds used a delayed video image to locate a sticker on themselves C?e//task) or a stuffed animal (other task). 2 tasks were positively correlated with age and vocabulary partialed out. Experiment 3 used a search task to assess whether children have particular difficulty using external representations that conflict with their expectations: 3- and 4-year-olds were informed of an object's location verbally or through video; on half of the trials, this information conflicted with children's initial belief. Three-yearolds performed worse than 4-year-olds on conflict trials, indicating that assessments of self and other understanding may reflect children's ability to reason about conflicting external representations. Assessments of cognitive development routinely require children to understand and use external representations, such as mirror images, drawings, and speech. However, children's use of external representations is an important topic in its own right (e.g., Bialystok, 1999; DeLoache, 1991; Liben, 1999), and difficulty using external representations may contribute to poor performance on tests that were designed to assess other aspects of children's cognition, such as their self-concept or their understanding of belief. As Troseth and DeLoache (1998) put it, The medium can obscure the message (p. 950). In the present study, we first used external representations to assess children's self-concept and then explored the extent to which children's performance on our tests reflected their developing ability to use external representations.