Journal article
Design and evaluation of line symbolizations for origin–destination flow maps
Information visualization, Vol.16(4), pp.309-331
10/2017
DOI: 10.1177/1473871616681375
Abstract
We present the results of a user study comparing variants of commonly used line symbolizations for directed origin–destination flow maps. Our design and evaluation consisted of five line symbolizations that employ a combination of following visual variables: arrowheads, origin–destination coloring (color hue, and value), line shortening, line width, tapered edges (varying width from wide to narrow, and narrow to wide), and curvature asymmetry and strength. To guide our evaluation, we used a task-by-type typology and chose four representative tasks that are commonly used in flow map reading: identifying dominant direction of flows, flows with the highest magnitude (volume), spatial focusing of long flows toward a destination, and clusters of high net-exports (net-outflow). We systematically analyzed user responses and task performance which we measured by task completion time and accuracy. We designed a web-based flow mapping and testing framework and recruited the participants from Amazon Mechanical Turk. To demonstrate the application and user experiment, we used 16 commodity flow data sets in the United States from 2007 and systematically rotated the layouts to evaluate the effect of layout orientation. From this study, we can conclude that there is potential usefulness for all of the five symbolizations we tested; however, the influence of the design on performance and perception depends on the type of the task. Also, we found that data and layout orientation have significant effects on performance and perception of patterns in flow maps which we attribute to the change in visual saliency of node and flow patterns in relation to the way users scan the map. We recommend that the choice of line symbolization should be guided by a task taxonomy which end users are expected to perform. We discuss various design trade-offs and recommendations and potential future work for designing and evaluating line symbolizations for flow mapping.
Details
- Title: Subtitle
- Design and evaluation of line symbolizations for origin–destination flow maps
- Creators
- Caglar Koylu - The University of Iowa, Iowa City, IA, USADiansheng Guo - University of South Carolina, Columbia, SC, USA
- Resource Type
- Journal article
- Publication Details
- Information visualization, Vol.16(4), pp.309-331
- DOI
- 10.1177/1473871616681375
- ISSN
- 1473-8716
- eISSN
- 1473-8724
- Grant note
- DOI: 10.13039/100000169, name: Division of Behavioral and Cognitive Sciences, award: 0748813
- Language
- English
- Date published
- 10/2017
- Academic Unit
- Center for Social Science Innovation; Public Policy Center (Archive); Geographical and Sustainability Sciences
- Record Identifier
- 9983984534802771
Metrics
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