The use of exploratory procedures by blind and sighted adults and children.

The study examined exploratory procedures (EPs) of congenitally blind and sighted children and adults on a haptic match-to-sample task. The aim was to examine the influence of age, visual status, and familiarity on the use of EPs when people haptically examine the object properties of weight, size, exact shape, and texture. EPs in the first and last of four series of trials were compared. The results showed that all four groups chose the same dominant EP for examining the four different object properties, all of them in agreement with the ones found by Lederman and Klatzky (Cognitive Psychology 19:342-368, 1987). Children were found to use more EPs, rather than using only the most efficient EP, for the dimension under study. Overall, performance was affected more by age than by visual status, and repeating the task led to increased efficiency in all groups. To describe exploratory behaviors in more detail, actions were introduced. Actions are single or sequential hand movements occurring in parallel with the EPs or apart from the EPs. The use of actions explained, in part, individual variation among the participants.