iTrace : Interactive Tracing of Cross-View Data Relationships

TL;DR

iTrace tackles the challenge of tracing cross-view data relationships in multi-view visualizations by introducing interactive focus transitions that externalize and manipulable the user’s focus across views. It defines a formal design space with three tracing tasks and three tracing modes, and implements a prototype that uses focus markers, related-element copies, and dynamic transitions to guide navigation while reducing clutter. A user study with 30 participants demonstrates higher accuracy and shorter task times when using iTrace, especially as data complexity increases or when linkage bundling is employed, while also highlighting visual clutter and focus-visibility concerns. The work suggests broad generalization to other visualization types and outlines limitations and future directions, including scalability improvements and optimized rendering.

Abstract

Exploring data relations across multiple views has been a common task in many domains such as bioinformatics, cybersecurity, and healthcare. To support this, various techniques (e.g., visual links and brushing and linking) are used to show related visual elements across views via lines and highlights. However, understanding the relations using these techniques, when many related elements are scattered, can be difficult due to spatial distance and complexity. To address this, we present iTrace, an interactive visualization technique to effectively trace cross-view data relationships. iTrace leverages the concept of interactive focus transitions, which allows users to see and directly manipulate their focus as they navigate between views. By directing the user's attention through smooth transitions between related elements, iTrace makes it easier to follow data relationships. We demonstrate the effectiveness of iTrace with a user study, and we conclude with a discussion of how iTrace can be broadly used to enhance data exploration in various types of visualizations.

Figures (13)

• Figure 1: An example of the challenge on exploring related visual elements across views with visual links and highlights.
• Figure 2: 3 types of cross-view data relationships: (a) between visual elements, (b) between visual elements and views, and (c) between views. Each box shows a view, orange circles and gray squares are visual elements, and blue lines indicate relations.
• Figure 3: Three types of tracing: (a) individual oriented, tracing in a single direction; (b) group oriented, tracing in a constrained direction, and (c) cluster oriented, tracing in reflected directions. A blue/red arrow indicates tracing direction and dotted lines show a constrained range of tracing.
• Figure 4: Designs for supporting tracing: context switching (A): user focus shifts from one view to another, context enriching (B): moving related visual elements from another view to the current one, and context separating (C): placing related visual elements outside original views and near each other. A trapezoid shows a user's focus at a time. A blue arrow reveals a moving direction.
• Figure 5: Examples of externalizing a user's focus in iTrace. (A): iTrace creates a copy of each visual element involved in a cross-view data relationship and overlays them on existing views. (B): iTrace enables automatically moving a focus marker as a user moves a mouse pointer from its previously focused visual element. Orange circles and blue rectangles show the focus marker and copy of related visual elements in iTrace, respectively.