The development of a simple ballistic skill with and without visual control

80 randomly selected male Ss discriminated the "effort" required to perform a simple 1-handed ballistic aiming task: aligning a Fletcher's Trolley with a pointer placed at varying distances adjacent to an inclined wooden track. Groups were aged 5-6, 10-11, 15-16, and 18 or more yr., with 10 Ss able to see both hands and target while the other 10 could see neither. A split-plot factorial design was used. On excluding the 5-6 yr.-old "Nonvision" children, the remaining 7 sub-groups were shown to be homogeneous. Mean absolute error scores increased with Distance, and also with a decrease in Age. In the "Non-vision" condition accuracy was reduced still further for all Ss. Age, Vision, and Distance and the interaction of Age with Vision were all significant, p<.01.