The importance of design in learning from node-link diagrams

Diagrams organize by location. They give spatial cues for finding and recognizing information and for making inferences. In education, diagrams are often used to help students understand and recall information. This study assessed the influence of perceptual cues on reading behavior and subsequent retention. Eighty-two participants were assigned to one of four versions of a node-link diagram. The diagram consisted of header cells on the left and on top. These header cells organized the information in the body cells, which were connected by arrows. We used a between-subjects design with diagram orientation (header types on top or on the left) and cues orientation (arrows top–down or left–right) as independent variables. Reading process was measured through eye-tracking. Learning performance was assessed with a post test. The results showed that perceptual cues and header content had an additive effect on reading behavior. The reading patterns were strongest when the arrows and category headers both pointed in the same direction. This was reflected in recall. Participants performed better on post-test questions oriented on categories.