Managing split-attention and redundancy in multimedia instruction

Two experiments investigated alternatives to split‐attention instructional designs. It was assumed that because a learner has a limited working memory capacity, any increase in cognitive resources required to process split‐attention materials decreases resources available for learning. Using computer‐based instructional material consisting of diagrams and text, Experiment 1 attempted to ameliorate split‐attention effects by increasing effective working memory size by presenting the text in auditory form. Auditory presentation of text proved superior to visual‐only presentation but not when the text was presented in both auditory and visual forms. In that case, the visual form was redundant and imposed a cognitive load that interfered with learning. Experiment 2 ameliorated split‐attention effects by using colour coding to reduce cognitive load inducing search for diagrammatic referents in the text. Mental load rating scales provided evidence in both experiments that alternatives to split‐attention instructional designs were effective due to reductions in cognitive load. Copyright © 1999 John Wiley & Sons, Ltd.