Some cognitive processes and their consequences for the organisation and presentation of information

It has been known for a considerable time that when dealing with complex intellectual tasks, the Limited processing capacity of working memory is critical. Nevertheless, many commonly used instructional techniques ignore this factor and consequently impose an excessive cognitive load that interferes with the major learning mechanisms of schema acquisition and automation. For example, when solving unfamiliar problems, strategies are frequently employed that are effective in arriving at a solution but because of the cognitive load imposed, are ineffective with respect to learning. Empirical evidence suggests that if learning is the goal, solving large numbers of conventional problems may not be appropriate. Instead, goal-free problems and worked examples can reduce extraneous cognitive load and facilitate schema acquisition and automation. Similarly, when presenting new material, information structures that require learners to unnecessarily split their attention between multiple sources of information or assimilate redundant material can impose an excessive cognitive load that interferes with learning. Finally, while considerable empirical evidence about these effects is available, it is suggested that they will occur only when material is used which imposes a heavy cognitive load because of its intrinsic structure. Where the intrinsic structure of information imposes a relatively light cognitive load, the cognitive load imposed by instructional design may not be critical.