Summary and Analysis of
"A Focus+Context Technique Based on Hyperbolic Geometry for Visualizing Large Hierarchies" written by John Lamping, Ramana Rao, and Peter Pirolli of Xerox Palo Alto Research Center
By Tammara Combs
Summary
The purpose of this research was to explore and analyze a new focus+context technique for browsing large hierarchies. The researchers introduced their work in the context of other focus+context techniques developed in Information Visualization research. They introduce a new fisheye technique, the hyperbolic browser, which allows users to see detailed parts of a hierarchy in the context of the entire hierarchical structure. The hierarchy can display several generations of parents, siblings and children. The display of the hyperbolic browser can be manipulated to bring interesting nodes to focus. The hyperbolic browser can supposedly display up to ten times as many nodes as a standard 2-d hierarchy browser.
Problem and Related Work
While the paper was well written and informative, there were a couple of things that were not clearly explained. First, the replication of the hyperbolic browser is probably impossible because there were no specific details about the actual implementation. There were, however, comments and further details given about the algorithms used to complete the techniques.
The researchers repeatedly refer to a standard 2-d hierarchy browser, but they never mention the names or the layout of the 2-d browser they are referring to. Perhaps they should have included a list of the 2-d browsers they researched and maybe a more detailed description of what a standard 2-d hierarchy browser looks like.
I would have also liked to see (or have explained) a better description of what the hierarchy browser would be used for. I wanted to see a "typical day in life using the hyperbolic browser". This way I would have been able to see how the authors think this new technology could potentially impact the lives of its users.
The authors did a wonderful job of trying to bridge the gap between previous studies and their fisheye view approach for browsing hierarchies. However, it seems that the authors discounted the other browsers based upon what has already been implemented while they judged the hyperbolic browser based upon possibilities. For example, in the context of comparing the hyperbolic browser to the cone tree, the authors use such language as "the hyperbolic browser is… potentially useful…"
Perhaps this paper was not detailed enough for some readers. Since the paper is entitled "A Focus+Context Technique Based on Hyperbolic Geometry for Visualizing Large Hierachies", I was expecting to read something about hyperbolic geometry. However, the authors stated "We don’t expect the user to know or care about hyperbolic geometry." So then it appears as if the paper is somehow mis-titled.
Evaluation
For the evaluation of the hyperbolic browser, there was no experimental design explicitly stated. Nor were any great details given about the plan and evaluation of the design. The authors stated that they conducted a laboratory experiment. However, because of the lack of details given about the design, I could not determine if the four subjects they used for evaluation were enough.
The authors were not able to make many sound conclusions because there was no statistically significance found in the comparison of the hyperbolic browser and what they call a standard 2-d hierarchy browser. Nevertheless, this was a nice piece of work that can serve as an example for other HCI research. The idea behind this paper is that the researchers made some type of technology and had users test the technology. It is absolutely critical in building software (or hardware for that matter) to get user feedback.
Questions