George G. Robertson

Cone Trees: animated 3D visualizations of hierarchical information

The task of managing and accessing large information spaces is a problem in large scale cognition. Enwrging technologies for 3D visualization and interactive aninlaiion offer potential solutions to this problenl, especially when the structure of the information can be visualized. We describe one of these Information Visualtzaiion techniques, called the Cone Tree, which is used for visualizing hierarchical information structures. The hierarchy is presented in 3D to nlaxilnize effective use of available screen space and enable visualization of the whole structure. Interactive aninlation is used (,o shift sonle of the user’s cognitive load to the human perceptual system,

The perspective wall: detail and context smoothly integrated

Tasks that involve large information spaces overwhelm workspaces that do not support efiicient use of space and time. For example, case studies indicate that information often contains linear components, which can result in 2D layouts with wide, inefficient aspect ratios. This paper describes a technique called the Perspective W’aU for visualizing linear information by smoothly integrating detailed and contextual views. It uses hardware support for 3D interactive animation to fold wide 2D layouts into intuitive 3D visualizations that have a center panel for detail and two perspective panels for context. The resulting visualization supports efficient use of space and time.

The information visualizer, an information workspace

This paper proposes a concept for the user interface of information retrieval systems called an information workspace. The concept goes beyond the usual notion of an information retrieval system to encompass the cost structure of information from secondary storage to immediate use. As an implementation of the concept, the paper describes an experimental system, called the Information Visualizer, and its rationale. The system is based on (1) the use of 3D/Rooms for increasing the capacity of immediate storage avaitable to the user, (2) the Cognitive Co-processor scheduler-based user interface interaction architecture for coupling the user to information agents, and (3) the use of information visualization for interacting with information structure.

Data mountain: using spatial memory for document management

Effective management of documents on computers has been a central user interface problem for many years. One common approach involves using 2D spatial layouts of icons representing the documents, particularly for information workspace tasks. This approach takes advantage of human 2D spatial cognition. More recently, several 3D spatial layouts have engaged 3D spatial cognition capabilities. Some have attempted to use spatial memory in 3D virtual environments. However, there has been no proof to date that spatial memory works the same way in 3D virtual environments as it does in the real world. We describe a new technique for document management called the Data Mountain, which allows users to place documents at arbitrary positions on an inclined plane in a 3D desktop virtual environment using a simple 2D interaction technique. We discuss how the design evolved in response to user feedback. We also describe a user study that shows that the Data Mountain does take advantage of spatial memory. Our study shows that the Data Mountain has statistically reliable advantages over the Microsoft Internet Explorer Favorites mechanism for managing documents of interest in an information workspace.

The WebBook and the Web Forager: an information workspace for the World-Wide Web

The World-Wide Web has achieved global connectivity stimulating the transition of computers from knowledge processors to knowledge sources. But the Web and its client software are seriously deficient for supporting users’ interactive use of this information. This paper presents two related designs with which to evolve the Web and its clients. The first is the WebBook, a 3D interactive book of HTML pages. The WebBook allows rapid interaction with objects at a higher level of aggregation than pages. The second is the Web Forager, an application that embeds the WebBook and other objects in a hierarchical 3D workspace. Both designs are intended as exercises to play off against analytical studies of information workspaces.

Rapid controlled movement through a virtual 3D workspace

Computer graphics hardware supporting real-time interactive 3D animation has the potential to support effective user interfaces by enabling virtual 3D workspaces. However, this potential requires development of viewpoint movement techniques that support rapid and controlled movement through workspaces. Rapid movement through large distances avoids wasted work time; controlled movement near target objects allows the user to examine and interact with objects in the workspace. Current techniques for viewpoint movement typically use high velocities to cover distances rapidly, but high velocities are hard to control near objects. This paper describes a new technique for targeted viewpoint movement that solves this problem. The key idea is to have the user indicate a point of interest (target) on a 3D object and use the distance to this target to move the viewpoint logarithmically, by moving the same relative percentage of distance to the target on every animation cycle. the result is rapid motion over distances that slows as the viewpoint approaches the target object. The technique can be used with 2D and multidimensional input devices. We also extend the technique to move objects in the workspace.

Animated Transitions in Statistical Data Graphics

In this paper we investigate the effectiveness of animated transitions between common statistical data graphics such as bar charts, pie charts, and scatter plots. We extend theoretical models of data graphics to include such transitions, introducing a taxonomy of transition types. We then propose design principles for creating effective transitions and illustrate the application of these principles in DynaVis, a visualization system featuring animated data graphics. Two controlled experiments were conducted to assess the efficacy of various transition types, finding that animated transitions can significantly improve graphical perception.

The document lens

This paper describes a general visualization technique based on a common strategy for understanding paper documents when their structure is not known, whiclh is to lay the pages of a document in a rectangular array on a large table where the overall structure and distinguishing features can be seen. Given such a presentation, the user wants to quickly view parts of the presentation in detail while remaining in context. A fisheye view or a magnifying lens might be used for this, but they fail to adequately show the global context. The Document Lens is a 3D visualization for large rectangular presentations that allows the user to quickly focus on a part of a presentation while continuously remaining in context. The user grabs a rectangular lens and pulls it around to focus on the desired area at the desired magnification. The presentation outside the lens is stretched to provide a continuous display of the global context. This stretching is efficiently implemented with affine transformations, allowing text documents to be viewed as a whole with an interactive visualization.

The Task Gallery: a 3D window manager

The Task Gallery is a window manager that uses interactive 3D graphics to provide direct support for task management and document comparison, lacking from many systems implementing the desktop metaphor. User tasks appear as artwork hung on the walls of a virtual art gallery, with the selected task on a stage. Multiple documents can be selected and displayed side-by-side using 3D space to provide uniform and intuitive scaling. The Task Gallery hosts any Windows application, using a novel redirection mechanism that routes input and output between the 3D environment and unmodified 2D Windows applications. User studies suggest that the Task Gallery helps with task management, is enjoyable to use, and that the 3D metaphor evokes spatial memory and cognition.

Effectiveness of Animation in Trend Visualization

Animation has been used to show trends in multi-dimensional data. This technique has recently gained new prominence for presentations, most notably with Gapminder Trendalyzer. In Trendalyzer, animation together with interesting data and an engaging presenter helps the audience understand the results of an analysis of the data. It is less clear whether trend animation is effective for analysis. This paper proposes two alternative trend visualizations that use static depictions of trends: one which shows traces of all trends overlaid simultaneously in one display and a second that uses a small multiples display to show the trend traces side-by-side. The paper evaluates the three visualizations for both analysis and presentation. Results indicate that trend animation can be challenging to use even for presentations; while it is the fastest technique for presentation and participants find it enjoyable and exciting, it does lead to many participant errors. Animation is the least effective form for analysis; both static depictions of trends are significantly faster than animation, and the small multiples display is more accurate.