This study explored the effects of the degree of exphcitness used to show movement and manipulation in teaching visual concepts through television. The review of the relevant theories highlighted the importance of individual differences in cognitive processing skills. The research question was formulated in terms of an aptitude treatment interaction. The aptitude of spatial ability was expected to interact with the level of exphcitness of moving visual sequences. A sample of 200 school children were divided into a control and two treatment groups Spatial ability was measured using a paper-folding test. The two television treatments, explicit and implicit, varied as to the degree of movement used to illustrate visual concepts and processes. An immediate comprehension test revealed no differences between the treatment groups. A test of retention administered three weeks later, showed a significant difference in favour of the explicit group Spatial ability was shown to be a significant moderating variable on both tests. No interaction between the variables was found.