Understanding how motor skills are learned influences how one teaches effective motor skill attainment. Educators must ask, "Does repetitive practice of the same task make for better performance or does contextual variability (random practice) offer some benefit when learning motor skills?" Studies on the effects of Contextual Interference may provide some insight. Contextual interference (CI) studies typically use simple tasks involving movements already acquired by adults, which may account for random practice benefits. In contrast, children do not consistently demonstrate CI effects, as tasks usually require acquisition of a new movement pattern. In this experiment, adults and children ((8-10 yrs old) threw a Frisbee to targets for 54 trials under random or blocked conditions. Having had considerable throwing experience with other throwing objects, adults were expected to benefit from random practice. For children, a blocked practice advantage was predicted as it provides for devising and stabilizing a suitable movement pattern. Retention/retraining trials were administered 30 minutes after acquisition and seven days later. Two transfer tests were given after the delayed retention test: (a) same throwing object/different target distances (SODT), which required re-scaling the practiced movement, and (b) different throwing object (ropeball)/same target distances (DOST) which required a new movement pattern. Throwing accuracy was measured by absolute error from the target. Both age groups showed a blocked practice benefit on retention and SODT transfer tests. Findings from this experiment suggest that task variables and stage of learning are important determinants of CI effects and thus should influence how we teach motor skill attainment.