Issue No. 05 - May (2012 vol. 18)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TVCG.2011.110
Zhanping Liu , Dept. of Comput. Sci., Kentucky State Univ., Frankfort, KY, USA
Shangshu Cai , Center for Risk Studies & Safety, Univ. of California at Santa Barbara, Goleta, CA, USA
J. Edward Swan , Dept. of Comput. Sci. & Eng., Mississippi State Univ., Starkville, MS, USA
Robert J. Moorhead , Electr. & Comput. Eng. Dept., Mississippi State Univ., Starkville, MS, USA
J. P. Martin , Lockheed Martin/U.S. Army Res. Lab., Aberdeen Proving Ground, MD, USA
T. J. Jankun-Kelly , Dept. of Comput. Sci. & Eng., Mississippi State Univ., Starkville, MS, USA
This paper presents a 2D flow visualization user study that we conducted using new methodologies to increase the objectiveness. We evaluated grid-based variable-size arrows, evenly spaced streamlines, and line integral convolution (LIC) variants (basic, oriented, and enhanced versions) coupled with a colorwheel and/or rainbow color map, which are representative of many geometry-based and texture-based techniques. To reduce data-related bias, template-based explicit flow synthesis was used to create a wide variety of symmetric flows with similar topological complexity. To suppress task-related bias, pattern-based implicit task design was employed, addressing critical point recognition, critical point classification, and symmetric pattern categorization. In addition, variable-duration and fixed-duration measurement schemes were utilized for lightweight precision-critical and heavyweight judgment-intensive flow analysis tasks, respectively, to record visualization effectiveness. We eliminated outliers and used the Ryan REGWQ post-hoc homogeneous subset tests in statistical analysis to obtain reliable findings. Our study shows that a texture-based dense representation with accentuated flow streaks, such as enhanced LIC, enables intuitive perception of the flow, while a geometry-based integral representation with uniform density control, such as evenly spaced streamlines, may exploit visual interpolation to facilitate mental reconstruction of the flow. It is also shown that inappropriate color mapping (e.g., colorwheel) may add distractions to a flow representation.
user interfaces, data visualisation, interpolation, pattern classification, statistical analysis, flow representation, 2D flow visualization user study, explicit flow synthesis, grid-based variable-size arrow, streamlines variant, line integral convolution variant, colorwheel map, rainbow color map, geometry-based techniques, texture-based techniques, data-related bias reduction, topological complexity, pattern-based implicit task design, critical point recognition, critical point classification, symmetric pattern categorization, variable-duration measurement scheme, fixed-duration measurement scheme, lightweight precision-critical flow analysis task, heavyweight judgment-intensive flow analysis task, visualization effectiveness, outliers, Ryan REGWQ post-hoc homogeneous subset test, statistical analysis, texture-based dense representation, geometry-based integral representation, visual interpolation, flow mental reconstruction, Visualization, Image color analysis, Color, Force, Streaming media, Synthesizers, Electronic mail, evenly spaced streamlines., Index Terms—Flow visualization, user study, visualization effectiveness, flow synthesis, task design, test strategy, LIC
R. J. Moorhead, J. E. Swan, Shangshu Cai, Zhanping Liu, J. P. Martin and T. J. Jankun-Kelly, "A 2D Flow Visualization User Study Using Explicit Flow Synthesis and Implicit Task Design," in IEEE Transactions on Visualization & Computer Graphics, vol. 18, no. , pp. 783-796, 2012.