Evaluating Cognitive Load: Force-directed Layout vs. Chord Layout

Abstract

Understanding cognitive processes during the interaction with visualizations, specifically limitations of working memory, opens a new perspective on evaluations and encourages a more user-centric design approach. In a user study we evaluated two graph data visualization approaches (i.e., the force-directed layout and the Chord layout) using a cognitive load questionnaire to assess the three load types: intrinsic, extraneous, and germane load. Tasks were designed to encourage insight and sensemaking in the participants during the evaluation. This type of evaluation helps to assess the users' mental processes during sensemaking and graph reading in the underlying layouts. Further, such study findings would help visualization designers in choosing the appropriate layout type for their graph data.