Current Projects: 2D versus 3D GUIs for file and document managements.

Revisiting 2D vs 3D Implications on Spatial Memory

Prior research has shown that the efficient use of graphical user interfaces strongly depends on human capabilities for spatial cognition. Although it is tempting to believe that moving from two- to three-dimensional user interfaces will enhance user performance through natural support for spatial memory, it remains unclear whether 3D displays provide these benefits. An experiment by Tavanti and Lind (2001) provides the most compelling result in favour of 3D. Their participants recalled the location of letters of the alphabet more effectively when using a 3D interface than when using a 2D one. The experiment reported in this paper is based on Tavanti and Lind's, but it controls some previously uncontrolled factors. The results strongly suggest that the effectiveness of spatial memory is unaffected by the presence or absence of three-dimensional perspective effects in monocular static displays. They also show that user interface items are more effectively memorised when personally meaningful and visually distinctive.

The 2D interface The 3D interface

Co-researcher (email): Bruce McKenzie

Evaluating the Effectiveness of Spatial Memory in 2D and 3D Physical and Virtual Environments

User interfaces can improve task performance by exploiting the powerful human capabilities for spatial cognition. This opportunity has been demonstrated by many prior experiments. It is tempting to believe that providing greater spatial flexibility---by moving from flat 2D to 3D user interfaces---will further enhance user performance. This paper describes an experiment that investigates the effectiveness of spatial memory in real-world physical models and in equivalent computer-based virtual systems. The models constrain to varying degrees the user's freedom to use depth and perspective in spatial arrangements of images representing web pages. Results show that the subjects' performance deteriorated in both the physical and virtual systems as their freedom to locate items in the third dimension increased. Subjective measures reinforce the performance measures, indicating that users found interfaces with higher dimensions more `cluttered' and less efficient.

3D or Not 3D? Evaluating the Effect of the Third Dimension in a Document Management System

Several recent research systems have provided interactive three-dimensional (3D) visualisations for supporting everyday work such as file- and document-management. But what improvements do these 3D interfaces offer over their traditional 2D counterparts? This paper describes the comparative evaluation of two document management systems that differ only in the number of dimensions used for displaying and interacting with the data. The 3D system is heavily based on Robertson et al.'s Data Mountain, which supports users in storing, organising and retrieving `thumbnail' representations of documents such as bookmarked web-pages. Results show that our subjects were faster at storing and retrieving pages in the display when using the 2D interface, but not significantly so. As expected, retrieval times significantly increased as the number of thumbnails increased. Despite the lack of significant differences between the 2D and 3D interfaces, subjective assessments showed a significant preference for the 3D interface.

An Evaluation of Cone Tree Interfaces.

Cone Trees are an appealing interactive 3D visualization technique for hierarchical data structures. They were originally intended to maximise effective use of available screen space and to better exploit the abilities of the human perceptual system. Prior work has focused on the fidelity of the visualization rather than providing empirical user studies. This paper describes the design, implementation and evaluation of a low-fidelity animated and rapidly interactive 3D cone tree system. Results of the evaluation show that our subjects were slower at locating data using cone trees than when using a `normal' tree browser, and that their performance deteriorated rapidly as the branching factor of the data-structure increased. Qualitative results, however, indicate that the subjects were enthusiastic about the cone tree visualization and that they felt it provided a better `feel' for the structure of the information space.

A simple Cone Tree interface

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