1. 1/25 Visualizing Social Networks Ryan Yee

2. 2/25 Plan Introduction and terminology Vizster NodeTrix MatLink Applications to Multi-agent systems

3. 3/25 Terminology Graph Model G = (V,E)‏ Graph Visualization Network / Node-Link Adjacency Matrix

4. 4/25 Node-Link Vertices represented by nodes Edges represented by links

5. 5/25 Adjacency Matrix Vertices represented by rows/columns Edges represented by cells Edges are directed

6. 6/25 Node-link vs. Adjacency Matrix Much easier to trace path in node-link Much easier to compare degree in matrix

7. 7/25 Problems…? Social data is: Locally dense Traditional node-link excellent for overall structure but less so for dense Adjacency excellent for dense structures but not effective for overall structure

8. 8/25 Vizster: visualizing Online Social Networks (Heer, Boyd)‏ Visualization of friends Focuses on subset of known friends Spring-based layout algorithm Spring strength based on vertex degree Designed for finding clusters

9. 9/25 Vizster: 1 & 2 Degree

10. 10/25 Vizster: path finding

11. 11/25 Vizster: Focus

12. 12/25 Vizster: Searching

13. 13/25 Vizster: Xray Mode 1

14. 14/25 Vizster: Agglomerative Clustering

15. 15/25 Vizster: Xray Mode 2

16. 16/25 NodeTrix: A Hybrid Visualization of Social Networks (Henry, Fekete, McGuffin)‏ Overall layout is LinLog EnergyBased clustering By default node-link visualization Interaction used to select subgraph and transform into adjacency matrix Excellent for viewing clusters

17. 17/25 Nodetrix

18. 18/25 NodeTrix: Bridge Identification

19. 19/25 NodeTrix: Cliques

20. 20/25 MatLink: Enhanced Matrix Visualization for Analyzing Social Networks (Henry, Fekete)‏ Matlink is a adjacency matrix enhanced with links for the current path Nodes are the “row/columns” Much easier to follow path Allows reordering of rows/columns: find cliques easier

21. 21/25 Matlink: NL, MAT, MatLink

22. 22/25 Matlink

23. 23/25 Relation to Multi-agent systems agents are sociable need to cooperate and communicate in order to meet a goal Graph visualizations are more scalable than a ladder visualization ladder visualization is messy for two to three agents but ladder is used because it expresses time well

24. 24/25 Ladder vs. Node-Link AliceBob what time is it? 5 o'clock Thanks

25. 25/25 [1] J. Heer and D. Boyd. Vizster: Visualizing Online Social Networks. In Proceedings of the 2005 IEEE Symposium on Information Visualization, pages 33–40, 2005. [2] N. Henry and J. Fekete. MatLink: Enhanced Matrix Visualization for Analyzing Social Networks. LECTURE NOTES IN COMPUTER SCIENCE, 4663:288, 2007. [3] N. Henry, J.D. Fekete, and M.J. McGuffin. NodeTrix: A Hybrid Visualization of Social Networks. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS, pages 1302–1309, 2007.