Evaluating the Comprehension of Euler Diagrams

We describe an empirical investigation into layout criteria that can help with the comprehension of Euler diagrams. Euler diagrams are used to represent set inclusion in applications such as teaching set theory, database querying, software engineering, filing system organisation and bio-informatics. Research in automatically laying out Euler diagrams for use with these applications is at an early stage, and our work attempts to aid this research by informing layout designers about the importance of various Euler diagram aesthetic criteria. The three criteria under investigation were: contour jaggedness, zone area inequality and edge closeness. Subjects were asked to interpret diagrams with different combinations of levels for each of the criteria. Results for this investigation indicate that, within the parameters of the study, all three criteria are important for understanding Euler diagrams and we have a preliminary indication of the ordering of their importance

Movement as an Aid to Understanding Graphs

This paper describes a graph visualization method that attempts to aid the understanding of graphs by adding continuous local movement to graph diagrams. The paper includes a discussion of some of the many different kinds of potential graph movement and then describes an empirical trial that was conducted to investigate whether one kind of movement helps with a particular graph comprehension task. Although the results of the trial are promising, the degree of benefit afforded by the movement varies between graphs and the paper includes a discussion about graph features which may account for this discrepancy