Reducing cognitive load by mixing auditory and visual presentation modes.

This article reports findings on the use of a partly auditory and partly visual mode of presentation for geometry worked examples. The logic was based on the split-attention effect and the effect of presentation modality on working memory. The split-attention effect occurs when students must split their attention between multiple sources of information, which results in a heavy cognitive load. Presentation-modality effects suggest that working memory has partially independent processors for handling visual and auditory material. Effective working memory may be increased by presenting material in a mixed rather than a unitary mode. If so, the negative consequences of split attention in geometry might be ameliorated by presenting geometry statements in auditory, rather than visual, form. The results of 6 experiments supported this hypothesis. In recent years, working memory limitations have been identified as a major factor that needs to be considered when instruction is designed. Researchers have used cognitive load theory (e.g., Sweller, 1988, 1989, 1993, 1994) to sug-gest that many commonly used instructional procedures are