Research Publications
P. Bergström, M. Chan, M. Dale, and E. James Whitehead, Jr. Sapphire: Composite Hypertext Document Structures. Poster in Proceedings of the 15th ACM Conference on Hypertext and Hypermedia, August 9-13, 2004, Santa Cruz, California, USA. [PDF]
P. Bergström. Circleview: Scalable visualization and navigation of citation networks. Undergraduate thesis, School of Engineering, University of California at Santa Cruz, Santa Cruz, California, USA. December 2004.
P. Bergström and E. J. Whitehead. Jr. Circleview: Scalable visualization and navigation of citation networks. In Proceedings of the 2006 Symposium on Interactive Visual Information Collections and Activity, June 19, 2006, College Station, Texas, USA. [PDF]
P. Bergström. Augmenting digital libraries using web-based visualizations. Master’s thesis, Santa Clara University, Department of Computer Engineering, Santa Clara, California, USA. June 24, 2009. [PDF]
P. Bergström and D. C. Atkinson. Digital Library Visualization Using SproutCore and SVG. In Proceedings of the Seventh International Conference on Scalable Vector Graphics, October 2-4, 2009, Mountain View, California, USA. [HTML]
P. Bergström and D. C. Atkinson. Augmenting the Exploration of Digital Libraries with Web-Based Visualizations. In Proceedings of the Fourth International Conference on Digital Information Management, November 2-4, 2009, Ann Arbor, Michigan, USA. [PDF]
Master’s Research
PaperCube Demo
Introduction to PaperCube Beta from Peter Bergström on Vimeo.
Thesis Abstract
The main goal of my research was two-fold. First, to develop and test the effectiveness of an application that can augment a scholar’s interaction with a digital library and explore bibliographic meta data using a defined set of visualizations. These visualizations needed to provide different levels of visibility into a paper’s citation network without losing focus of the currently viewed paper. The application, called PaperCube, needed to support navigation between papers and, to a limited extent, the authors of those papers. The application needed to be able to provide insight into author to author citation networks as well as collaboration relationships.
The hypothesis was that by replacing the traditional webpage-based paradigm with a suite of visualizations that expose various dimensions of bibliographic meta data, the a researcher could gain new insights and find relationships that were not previously apparent. Furthermore, by making the experience spatial, the aim was to see if researchers were able to find what they were looking for more quickly and intuitively.
The second goal was to push the limits of modern web browsers. By using web standards-based technologies, the goal was to explore the possibility of creating a dynamic, desktop-like experience that incorporates rich, interactive visualizations.
PaperCube was written using the SproutCore JavaScript framework, which is geared towards the creation of highly interactive, cloud, or thick-client applications in the web browser. Using only JavaScript and standards-based rendering technologies such as Scalable Vector Graphics, Canvas tag, HTML and CSS, PaperCube allows users to browse a version of the CiteSeer digital library and view paper and author relationships using a set of dynamic visualizations.
Leveraging the powerful features in SproutCore including bindings and observers, PaperCube aims to deliver unparalleled interactivity within the confines of a web browser. Bindings and observers enabled PaperCube to easily implement resolution independence in its visualizations. Resolution independence was key because citation networks can be very large. By adjusting a slider control in the UI, a visualization can be zoomed in using vector-based transforms without needing to explicitly redraw. Furthermore, through the use of bindings, slider controls can dynamically alter the display parameters of the visualizations, permitting the depth of a paper citation network to be adjusted or the thresholds that determine if a node should be displayed as part of the graph changed.
Stemming from the need for a flexible graph API for various views in PaperCube, the SVG-based NodeGraph class was created as a generalized solution that can display any type of relational data as an undirected graph. The class is not PaperCube-specific and could be easily integrated into other applications.
PaperCube was validated through a user study which showed that it was very useful when it comes to augmenting digital library search by reducing the “cognitive load” put on a scholar and aiding the “discoverability” of new research material. Furthermore, it was shown that participants thought that it was “visually exciting and intuitive” application and an “amazing example of the apps that well be seeing on the web in a couple of years.”
Related Publications
P. Bergström. Augmenting digital libraries using web-based visualizations. Master’s thesis, Santa Clara University, Department of Computer Engineering, Santa Clara, California, USA. June 24, 2009. [PDF]
P. Bergström and D. C. Atkinson. Digital Library Visualization Using SproutCore and SVG. In Proceedings of the Seventh International Conference on Scalable Vector Graphics, October 2-4, 2009, Mountain View, California, USA. [HTML]
P. Bergström and D. C. Atkinson. Augmenting the Exploration of Digital Libraries with Web-Based Visualizations. In Proceedings of the Fourth International Conference on Digital Information Management, November 2-4, 2009, Ann Arbor, Michigan, USA. [PDF]
Undergraduate Research
I have conducted two research projects as an undergraduate at the University of California at Santa Cruz. Below you can read the abstracts for both papers, download their PDFs, as well as access online demos of the two projects. (Demos will be forthcoming on the new site.)
CircleView
CircleView is a citation network browser that uses circles around circles as its visualization method to show a focus paper and two levels of its citation network. This method scales to varying numbers of papers and references, and has a structured layout that makes the visualization more readable. Bibliographic metadata is available via mouseover for all displayed papers. General requirements are presented for citation network visualization and navigation tools. An important requirement is the ability to integrate with existing institutional digital libraries, satisfied by CircleView’s use of web browser facilities for its user interface. CircleView is shown to have good visualization and performance scalability characteristics.
Published at the 2004 ACM Conference on Hypertext and Hypermedia as a poster.
Related Publications
P. Bergström. Circleview: Scalable visualization and navigation of citation networks. Undergraduate thesis, School of Engineering, University of California at Santa Cruz, Santa Cruz, California, USA. December 2004.
P. Bergström and E. J. Whitehead. Jr. Circleview: Scalable visualization and navigation of citation networks. In Proceedings of the 2006 Symposium on Interactive Visual Information Collections and Activity, June 19, 2006, College Station, Texas, USA. [PDF]
Sapphire
Inspired by Theodor Nelson’s Xanadu and vLit concepts, Sapphire implements a composite document structure in which formatting is specified external to the text. Formatting overlays are rendered over the text, so multiple overlays may be stacked according to user preference. Sapphire supports the viewing of a document composed from multiple fragments, and viewing the original source of each fragment. Other features include annotation on the composite documents and the storing and restoring of document trails in the spirit of the Memex. An editor function permits the creation and editing of Sapphire composite documents. This project served as an exploration of the potential of alternative hypertext implementations to the pervasive HTML standard in use today.
Related Publications
P. Bergström, M. Chan, M. Dale, and E. James Whitehead, Jr. Sapphire: Composite Hypertext Document Structures. Poster in Proceedings of the 15th ACM Conference on Hypertext and Hypermedia, August 9-13, 2004, Santa Cruz, California, USA. [PDF]