Results confirmed that children differentially use knowledge of results and suggested that any description of motor skill acquisition must account for the complex interaction between developmental level and the difficulty of the task at hand. (Author/DB)

Children and adults were tested on six speeded perceptual-motor and cognitive tasks, including a (1) response time task; (2) button tapping task; (3) pegboard task; (4) coding task; (5) picture matching task; and (6) mental addition task. Age-related change in processing time on most of these tasks was described by a single exponential function.…