Knowledge is not everything: analysis of children's performance on a haptic comparison task

The relative effects of developmental level and domain-specific knowledge on children's ability to identify and make similarity decisions about object concepts based only on haptic (touch) information were investigated. Children aged 4-9 years with varying levels of dinosaur knowledge completed a cross-comparison task in which they haptically explored pairs of familiar (dinosaur) and unfamiliar (sea creature) models that varied in terms of their degree of differentiability. Older children explored models more exhaustively, found more differentiating features and consequently made fewer errors than younger children did. High knowledge enabled children to identify models correctly, but was also associated with the use of a hypothesis testing strategy, which led children to make greater numbers of "miss" errors on the cross-comparison task. Performance in the control domain illustrated that the hypothesis testing strategy was specific to the high knowledge domain. Potential explanations for the role of knowledge and development in haptic exploration are considered.