A comparison of linear and mosaic diagrams for set visualization

Abstract

Linear diagrams have been shown to compare favourably to better known forms of set visualization, such as Venn and Euler diagrams, in supporting non-interactive assessment of set relationships. Recent studies that compared several variants of linear diagrams have demonstrated that users perform best at tasks involving identification of intersections, disjointness and subsets when using a horizontally drawn linear diagram with thin lines representing sets and employing vertical lines as guide lines. The essential visual task the user needs to perform in order to interpret this kind of diagram is vertical alignment of parallel lines and detection of overlaps. Space-filling mosaic diagrams which support this same visual task have been used in other applications, such as the visualization of schedules of activities, where they have been shown to be superior to linear Gantt charts. In this article, we present an experimental comparison of linear and mosaic diagrams for visualization of set relationships, in terms of accuracy, time-to-answer and subjective ratings of perceived task difficulty. The findings show that the two visualizations are largely similar with respect to these measures, suggesting that the choice of one or the other may be solely guided by other visual design considerations. Mosaic diagrams might be more suitable, for instance, in cases where miniature diagrams representing overviews of relations in different collections of sets are required, such as in small-multiples displays.

Visualizing narrative patterns in online news media

“…Although our current prototype has a limited number of interactive tools, these could be extended easily along the lines of interactive functionality that we have identified. We are also aiming to investigate a number of alternatives to the time-sets visualization, including the use of space-filling mosaics [23], which have been shown to be more effective than linear diagrams for some tasks involving visual comparisons of set relationships [24], but without involving comparisons across multiple axes or time.…”

“…Although the use of the visual element of line length [5] to represent cardinality in linear diagrams would be an obvious choice, and has previously been suggested [13,24], it has not been widely adopted or utilized in existing visualizations. In most cases, the drawing algorithm used for creating linear diagrams aims to create the most compact, and the least segmented, version of the diagram using multiples of a basic (shortest) unit of line length for each intersection, without representing cardinalities.…”

On the Readability of Abstract Set Visualizations

“…Matrixbased methods scale well, but have a strong dependency on row and column ordering, are less intuitive for nonexperts, and require interaction with a non-trivial interface for the more complex set visualization tasks. Closely related are linear diagrams [7], [35], [36], where again each set is a row in a table. The columns, however, do not represent individual elements, but rather non-empty set intersections.…”

“…Further evaluations considered techniques such as Euler diagrams, linear diagrams, and mosaic diagrams, all of which do not represent individual elements and thus used only set-based tasks [3], [7]. They showed that linear diagrams outperformed Euler diagrams and were on par with mosaic diagrams.…”

“…Some considered spatial set systems with embedded elements [2], or focused on different visual parameters in a single type of visualization style such as Euler diagrams [3] or LineSets [4]. Others studied specific tasks in combined visualizations of set systems and underlying networks [5], [6] or compared visualization techniques that do not show individual elements such as linear and mosaic diagrams [7].…”