A Comparison of the Readability of Graphs Using Node-Link and Matrix-Based Representations

Abstract

In this paper, we describe a taxonomy of generic graph related tasks and an evaluation aiming at assessing the readability of two representations of graphs: matrix-based representations and nodelink diagrams. This evaluation bears on seven generic tasks and leads to important recommendations with regard to the representation of graphs according to their size and density. For instance, we show that when graphs are bigger than twenty vertices, the matrix-based visualization performs better than node-link diagrams on most tasks. Only path finding is consistently in favor of nodelink diagrams throughout the evaluation.

An extended evaluation of the readability of tapered, animated, and textured directed-edge representations in node-link graphs

“…Various approaches can be used to overcome this, such as user interaction, using a matrix instead of a nodelink representation, improving the node-link layout, or improving the directed-edge representation. However, user interaction is not suited for statically depicted graphs such as printouts; matrix representations are less intuitive than node-link graphs [12,17]; and layout improvement is generally tackled by node-placement optimization, while the arrowhead-clutter problem stems from a suboptimal edge representation. We were therefore motivated to focus our efforts on finding improved directed-edge representations.…”

Design Change Model for Effective Scheduling Change Propagation Paths

“…Change propagation paths can be visualized in various forms, including design structure matrices [16] , change risk plot [17] , propagation networks [18] and propagation trees [19] . When displaying a large and complex product with too many direct and indirect linkages, it is uneasy to see every path clearly [20] and unwise to analyze every propagation path with reduced efficiency.…”

Data-Visual Relationships to Subject Performance and Eye Movements

“…The tasks will consist of answering questions about the images [Foster 2003, Peebles and Cheng 2003, Ghoniem et al 2004] involving estimation, comparison or matching between visual elements, and visual search to identify, count, or navigate through features. Half of the stimuli will be accompanied by questions posed before the trials, and half after the trials, to determine the effectiveness of a graphic in terms of how navigable it is in the former case and how memorable it is in the latter case.…”

“…The questions will be of either a local or global character, to see what effects the distribution of intended fixation points in a visual search, for example, has on eye movements and task performance. Problem-solving questions used for comparing the effectiveness of a network diagram and a matrix representation of the same data might include: estimate the number of nodes and links, find a particular node or link (such as the most connected node or a link with a particular label), and find a path or common neighbor between two nodes [Ghoniem et al 2004]. …”