Effects of varying force production in practice schedules of children learning a discrete motor task.

The variability of practice prediction from Schmidt's Schema Theory involving transfer and retention was tested when manipulating only the performance parameter of over-all force. Children (n = 120) of two age groups performed a 15-in (39.1 cm) arm movement on a linear slide modified to allow manipulating the force required to move the car on the slide. No significant differences between the variable group and the constant practice group were found for either the 10 transfer or 5 retention trials. Mean absolute errors were ordered in favor of the constant practice group for both transfer and retention. For the first transfer trial a significant difference was found; constant practice groups performed better. This finding is contrary to predictions of schema theory as well as evidence from children as subjects.