The influence of leads on cognitive load and learning in a hypertext environment

The purpose of this study was to determine the effect of leads (or hypertext node previews) on cognitive load and learning. Leads provided a brief summary of information in the linked node, which helped orient the reader to the linked information. Dependent variables included measures of cognitive load: self-report of mental effort, reading time, and event-related desynchronization percentage of alpha, beta and theta brain wave rhythms; and learning performance: a recall task, and tests of domain and structural knowledge. Results indicated that use of leads reduced brain wave activity that may reflect split attention and extraneous cognitive load, and improved domain and structural knowledge acquisition. Further, findings provide insights into differentiating the types of cognitive load apparent in hypertext-assisted learning environments. Use of EEG measures allowed examination of instantaneous cognitive load, which showed that leads may be influencing germane load—reducing mental burden associated with creating coherence between two linked node. The self-report of mental effort measure appears more closely associated with overall and intrinsic load.