This Article 
 Bibliographic References 
 Add to: 
Design and Evaluation of MagnetViz—A Graph Visualization Tool
May 2012 (vol. 18 no. 5)
pp. 822-835
A. S. Spritzer, Univ. Fed. do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
Carla M. Dal Sasso Freitas, Inst. de Inf., Univ. Fed. do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
MagnetViz was designed for the interactive manipulation of force-directed graph layouts, allowing the user to obtain visualizations based on the graph topology and/or the attributes of its nodes and edges. The user can introduce virtual magnets anywhere in the graph and these can be set to attract nodes and edges that fulfill user-defined criteria. When a magnet is placed, the force-directed nature of the layout forces it to reorganize itself in order to reflect the changes in the balance of forces, consequently changing the visualization into one that is more semantically relevant to the user. This paper describes MagnetViz's concepts, illustrating them with examples and a case study based on a usage scenario. We also describe how the MagnetViz has evolved since its original version and present the evaluation of its latest version. This evaluation consists of two user studies aiming at assessing generated layout quality and how well the concepts can be apprehended and employed, and a task taxonomy assessment focusing on establishing which graph visualization tasks the technique is able to handle.

[1] G.D. Battista, P. Eades, R. Tamassia, and I.G. Tollis, Graph Drawing. Prentice Hall, 1999.
[2] I. Herman, I.C. Society, G. Melanon, and M.S. Marshall, "Graph Visualization and Navigation in Information Visualization: A Survey," IEEE Trans. Visualization and Computer Graphics, vol. 6, no. 1, pp. 24-43, Jan.-Mar. 2000.
[3] S. Wasserman, K. Faust, and D. Iacobucci, Social Network Analysis : Methods and Applications (Structural Analysis in the Social Sciences). Cambridge Univ. Press, Nov. 1994.
[4] B. Cheswick, H. Burch, and S. Branigan, "Mapping and Visualizing the Internet," Proc. USENIX Ann. Technical Conf., pp. 1-12, 2000,
[5] N. Henry, J.-D. Fekete, and M. McGuffin, "Nodetrix: Hybrid Representation for Analyzing Social Networks," ArXiv E-prints, vol. 705, May 2007.
[6] A.S. Spritzer and C.M.D.S. Freitas, "A Physics-Based Approach for Interactive Manipulation of Graph Visualizations," AVI '08: Proc. Working Conf. Advanced Visual Interfaces. pp. 271-278, 2008.
[7] B. Lee, C. Plaisant, C.S. Parr, J.-D. Fekete, and N. Henry, "Task Taxonomy for Graph Visualization," BELIV '06: Proc. AVI Workshop BEyond Time and Errors. pp. 1-5, 2006.
[8] T. Pattison, R. Vernik, and M. Phillips, "Information Visualisation Using Composable Layouts and Visual Sets," Proc. Asia-Pacific Symp. Information Visualisation, pp. 1-10, 2001.
[9] M. Wattenberg, "Visual Exploration of Multivariate Graphs," CHI '06: Proc. SIGCHI Conf. Human Factors in Computing Systems, pp. 811-819, 2006.
[10] B. Shneiderman and A. Aris, "Network Visualization by Semantic Substrates," IEEE Trans. Visualization and Computer Graphics, vol. 12, no. 5, pp. 733-740, Sept./Oct. 2006.
[11] A. Aris and B. Shneiderman, "Designing Semantic Substrates for Visual Network Exploration," Information Visualization, vol. 6, pp. 281-300, Dec. 2007.
[12] A. Bezerianos, F. Chevalier, P. Dragicevic, N. Elmqvist, and J.-D. Fekete, "Graphdice: A System for Exploring Multivariate Social Networks," Computer Graphics Forum, vol. 29, no. 3, pp. 863-872, 2010.
[13] A.J. Pretorius and J.J. van Wijk, "Visual Analysis of Multivariate State Transition Graphs," IEEE Trans. Visualization and Computer Graphics, vol. 12, no. 5, pp. 685-692, Sept./Oct. 2006.
[14] A.J. Pretorius and J.J. van Wijk, "Visual Inspection of Multivariate Graphs," EUROVIS '08: Proc. Eurographics/IEEE-VGTC Symp. Visualization, pp. 967-974, 2008.
[15] D. Archambault, T. Munzner, and D. Auber, "Grouseflocks: Steerable Exploration of Graph Hierarchy Space," IEEE Trans. Visualization and Computer Graphics, vol. 14, no. 4, pp. 900-913, July/Aug. 2008.
[16] S. Zhao, M. McGuffin, and M. Chignell, "Elastic Hierarchies: Combining Treemaps and Node-Link Diagrams," Proc. IEEE Symp. Information Visualization (INFOVIS '05), pp. 57-64, Oct. 2005.
[17] M.J. McGuffin and I. Jurisica, "Interaction Techniques for Selecting and Manipulating Subgraphs in Network Visualizations," IEEE Trans. Visualization and Computer Graphics, vol. 15, no. 6, pp. 937-944, Nov./Dec. 2009.
[18] D. Archambault, H.c. Purchase, and B. Pinaud, "The Readability of Path-Preserving Clusterings of Graphs," Computer Graphics Forum, vol. 29, no. 3, pp. 1173-1182, 2010.
[19] J.S. Yi, R. Melton, J. Stasko, and J.A. Jacko, "Dust & Magnet: Multivariate Information Visualization Using a Magnet Metaphor," Information Visualization, vol. 4, pp. 239-256, Oct. 2005.
[20] D. Tunkelang, "A Numerical Optimization Approach to General Graph Drawing," PhD dissertation, School of Computer Science, Carnegie Mellon Univ., 1999.
[21] T.M.J. Fruchterman and E.M. Reingold, "Graph Drawing by Force-Directed Placement," Software Practice and Experience, vol. 21, no. 11, pp. 1129-1164, 1991.
[22] L. Verlet, "Computer 'Experiments' on Classical Fluids. I. Thermodynamical Properties of Lennard-Jones Molecules," Physical Rev., vol. 159, no. 1, pp. 98-103, July 1967.
[23] T. Munzner, "A Nested Model for Visualization Design and Validation," IEEE Trans. Visualization and Computer Graphics, vol. 15, no. 6, pp. 921-928, Nov./Dec. 2009.

Index Terms:
user interfaces,data visualisation,directed graphs,task taxonomy assessment,MagnetViz tool,graph visualization tool,force-directed graph layout,graph topology,graph node,graph edge,virtual magnet,user-defined criteria,layout force,force balance,usage scenario,user studies,generated layout quality,Layout,Visualization,Magnetic separation,Shape,Data visualization,Topology,Color,social networks visualization.,Graph visualization,force-directed layout,evaluation
A. S. Spritzer, Carla M. Dal Sasso Freitas, "Design and Evaluation of MagnetViz—A Graph Visualization Tool," IEEE Transactions on Visualization and Computer Graphics, vol. 18, no. 5, pp. 822-835, May 2012, doi:10.1109/TVCG.2011.106
Usage of this product signifies your acceptance of the Terms of Use.