An initial examination of ease of use for 2D and 3D information visualizations of web content

We present a discussion and initial empirical investigation of user-interfa ce designs for a set of three Web browsers. The target end-user population we identified were experienced software engineers who maintained large Web sites or portals. The user study demonstrated the strengths and weaknesses of two conventional 2D browsers for this target user, as well as that of XM L3D, a novel browser that integrates an interactive 3D hyperbolic graph vie w with a more traditional 2D list view of the data. A standard collapse/exp and tree browser and a Web-based hierarchical categorization similar to Yah oo!, were competitively evaluated against XML3D. No reliable difference bet ween the two 2D browsers was observed. However, the results showed clear di fferences between XML3D and the 2D user interfaces combined. With XML3D, pa rticipants performed search tasks within existing categories reliably faste r with no decline in the quality of their responses. It was informally obse rved that integrating the ability to view the overall structure of the info rmation space with the ability to easily assess local and global relationsh ips was key to successful search performance. XML3D was the only tool of th e three that efficiently showed the overall structure within one visualizat ion. The XML3D browser accomplished this by combining a 3D graph layout vie w as well as an accompanying 2D list view. Users did opt to use the 2D user -interface components of XML3D during new category search tasks, and the XM L3D performance advantage was no longer obtained in those conditions. In ad dition, there were no reliable differences in overall user satisfaction acr oss the three user-interface designs. Since we observed subjects using the XML3D features differently depending on the kind of search task, future stu dies should explore optimal ways of integrating the use of novel focus + co ntext visualizations and 2D lists for effective information retrieval. The contribution of this paper is that it includes empirical data to demonstrat e where novel focus + context views might benefit experienced users over an d above more conventional user-interface techniques, in addition to where d esign improvements are warranted. (C) 2000 Academic Press.