Optimization of Cognitive Load in Conceptually Rich Hypertext: Effect of Leads

The hyperlinking feature of hypertext, which in the cognitive flexibility perspective encourages advanced learning (Spiro & Jehng, 1990), frequently overloads working memory according to the cognitive load theory (Sweller, 1988). One of such negative effects of hyperlinks is split attention. When two or more sources of information are separated in space (e.g., text located on different hypertext pages), information integration is compounded by intensive search-and-match processes, which are involved in cross-referencing mental representations, and, thus, it may place an unnecessary strain on limited working memory resources. One tool that seems to have the potential to reduce split attention and physically integrate different pages in hypertext systems is the lead. Leads are link comments that appear as a popup balloon when the mouse is over the hyperlink providing a one-sentence summary of the content of the linked page. The purpose of the present research study was to assess the effect of leads on cognitive load associated with split attention in the context of conceptually rich instructional hypertext.