Discussion The split attention effect
Many instructional materials require both a pictorial component and a textual component of information. Conventionally a graphic has been presented with the associated text above, below, or at the side. Such instructional presentations introduce a split attention effect where the student needs to attend to both the graphic and the text. Neither the graphic, nor the text, alone, provide sufficient information to enable understanding. The instructional material can only be understood after the student has mentally integrated the multiple sources of information. The portion of working memory that needs to be used in integrating the graphic and text is unavailable for the learning process. Consequently learning is ineffective.
Consider this conventional mathematics based example, taken from Sweller, Chandler, Tierney & Cooper (1990).