Visualizing & Exploring Networks using Semantic Substrates

12:00 noon, April 15, Tuesday, 2008, ST2, 430A

Speaker

Aleks Aris
PhD Candidate in Computer Science
Human-Computer Interaction Lab
University of Maryland, College Park
http://www.cs.umd.edu/~aris

Abstract

Visualizing and exploring network data has been a challenging problem for HCI (Human-Computer Interaction) Information Visualization researchers due to the complexity of representing networks (graphs). Research on this area has concentrated on improving the visual organization of nodes and links according to graph drawing aesthetics criteria, such as minimizing link crossings and the longest link length. Semantic substrates offer a different approach by which node locations represent node attributes. Users define semantic substrates for a given dataset according to the dataset characteristics and the questions, needs, and tasks of users. Then, the substrate is used to layout nodes of the network. Link visibility filters are provided to isolate various parts of the dataset and find meaningful relationships.

Datasets, such as legal precedent (with court decisions citing one another) and food-web (predator-prey relationships) have been explored using NVSS**, a network visualization tool to test and refine the semantic substrate approach. A case study approach is used for evaluation, during which insights and hypothesis are generated by users. The techniques are potentially applicable to other datasets such as social networks, business networks, and email communication. Semantic substrates promise a more controlled, focused, and understandable way of exploring networks.

Short Bio

Aleks Aris is a PhD candidate at the Computer Science Department of the University of Maryland, College Park. He is a member of the Human-Computer Interaction Laboratory (HCIL*) and his dissertation advisor is Dr. Ben Shneiderman. His current research interest is network visualization in the information visualization area of the human-computer interaction (HCI) field. Previously, he has also worked on TimeSearcher 2, a time-series visualization tool, and Treemap, a space-filling visualization tool. In 2004, he worked on the MyLifeBits project of Microsoft Research. Aleks Aris was awarded a teaching excellence award in 2003. He graduated from one of the Turkey's top-rated universities, Middle East Technical University, with a rank of 2 out of 120, where he was admitted with a rank of 26th out of 1,500,000 in the nationwide college entrance exam.

* HCIL is known as the earliest human-computer interaction (HCI) lab in the United States (25 years). In addition, the lab has ranked #2 in the number of citations received in 1990s (after Xerox PARC). Dr. Ben Shneiderman is the founding director of HCIL and receiver of the ACM SIGCHI Lifetime Achievement Award in 2001.

** NVSS web page: http://www.cs.umd.edu/hcil/nvss