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, 1988Sweller, , 1989Sweller, , 1993Sweller, , 1994 to suggest that many commonly used instructional procedures are inadequate because they require learners to engage in unnecessary cognitive activities that impose a heavy working memory load. Alternatives that reduce extraneous cognitive load have been devised. This research has been generated by the following assumptions concerning our basic cognitive architecture: (a) People have a very limited working memory that is able to hold and process only a few items of information at a time; (b) People have a huge long-term memory that is effectively unlimited in size; (c) Schema acquisition is a primary learning mechanism. Schemata are defined as cognitive constructs that permit people to categorize information in the manner in which it will be used (see Low & Over, 1990Low, Over, Doolan, & Michell, 1994;Sweller & Low, 1992 functions of storing information in long-term memory and of reducing working memory load by permitting people to treat multiple elements of information as a single element; (d) Automation of cognitive processes, including automatic use of schemata, is a learning mechanism that also reduces working memory load by effectively bypassing working memory. Automated information can be processed without conscious effort.A limited working memory is central to this architecture and central to cognitive load theory. Recent work has expanded researchers' knowledge of working memory characteristics and in turn, this work has the potential to expand the instructional techniques generated by cognitive load theory. In this article, we discuss the split-attention effect that previous research has suggested is a cognitive load phenomenon. The split-attention effect occurs when learners are required to divide their attention among and mentally integrate multiple sources of information. Mentally integrating multiple sources of information results in less effective acquisition of information than if learners are presented the same mater...