Ramana Rao

A focus+context technique based on hyperbolic geometry for visualizing large hierarchies

We present a new focus+context (fisheye) technique for visualizing and manipulating large hierarchies. Our technique assigns more display space to a portion of the hierarchy while still embedding it in the context of the entire hierarchy. The essence of this scheme is to lay out the hierarchy in a uniform way on a hyperbolic plane an d map this plane onto a circular display region. This supports a smooth blending between focus and context, as well as continuous redirection of the focus. We have developed effective procedures for manipulating the focus using pointer clicks as well as interactive dragging, and for smoothly an imating transitions across such manipulation. A laboratory experiment comparing the hyperbolic browser with a conventional hierarchy browser was conducted.

The table lens: merging graphical and symbolic representations in an interactive focus + context visualization for tabular information

We present a new visualization, called the Table Lens, for visualizing and making sense of large tables. The visualization uses a focus+context (fisheye) technique that works effectively on tabular information because it allows display of crucial label information and multiple distal focal areas. In addition, a graphical mapping scheme for depicting table contents has been developed for the most widespread kind of tables, the cases-by-variables table. The Table Lens fuses symbolic and graphical representations into a single coherent view that can be fluidly adjusted by the user. This fusion and interactivity enables an extremely rich and natural style of direct manipulation exploratory data analysis.

The hyperbolic browser: a focus + context technique for visualizing large hierarchies

We present a new focus 1 context technique based on hyperbolic geometry for visualizing and manipulating large hierarchies . Our technique assigns more display space to a portion of the hierarchy while still embedding it in the context of the entire hierarchy . We lay out the hierarchy in a uniform way on a hyperbolic plane and map this plane onto a display region . The chosen mapping provides a fisheye distortion that supports a smooth blending of focus and context . We have deveoped ef fective procedures for manipulating the focus using pointer clicks as well as interactive dragging and for smoothly animating transitions across such manipulation . Enhancements to the core mechanisms provide support for multiple foci , control of the tradeof f between node density and node display space , and for visualizing graphs by transforming them into trees .

Laying out and visualizing large trees using a hyperbolic space

We present a new focus+context (fisheye) scheme for visualizing and manipulating large hierarchies. The essence of our approach is to lay out the hierarchy uniformly on the hyperbolic plane and map this plane onto a circular display region. The projection onto the disk provides a natural mechanism for assigning more space to a portion of the hierarchy while still embedding it in a much larger context. Change of focus is accomplished by translating the structure on the hyperbolic plane, which allows a smooth transition without compromising the presentation of the context.

Rich interaction in the digital library

Effective information access involves rich interactions between users and information residing in diverse locations. Users seek and retrieve information from the sources—for example, file serves, databases, and digital libraries—and use various tools to browse, manipulate, reuse, and generally process the information. We have developed a number of techniques that support various aspects of the process of user/information interaction. These techniques can be considered attempts to increase the bandwidth and quality of the interactions between users and information in an information workspace—an environment designed to support information work (see Figure 1).

Bridging the paper and electronic worlds: the paper user interface

Since its invention millenia ago, paper has served as one of our primary communications media. Its inherent physical properties make it easy to use, transport, and store, and cheap to manufacture. Despite these advantages, paper remains a second class citizen in the electronic world. In this paper, we present a new technology for bridging the paper and the electronic worlds. In this new technology, the user interface moves beyond the workstation and onto paper itself. We describe paper user interface technology and its implementation in a particular system called XAX.

Protofoil: storing and finding the information worker's paper documents in an electronic file cabinet

Although the document imaging industry has taken off in the last few years, document image filing for the individual information worker is still not widespread or effective. In this paper, we focus on building an electronic tiling system for paper documents that supports the ad hoc, multifarious work of information workers. Motivated by interviews with researchers and a survey of descriptive studies of paper document filing, we have focussed on minimizing or delaying costs of document filing and supporting a rich variety of methods for accessing and using stored documents. We have implemented a prototype system called Protofoil for storing, retrieving, and manipulating paper documents as electronic images that integrates many user interface-paper and workstation—and information retrieval technologies. Protofoil has been tested through use in our laboratory. and has been deployed in a field study at a lawyer’s office.

Exploring large tables with the table lens

The Table Lens is a new technique for visualizing andmaking sense of large tables. By fusing symbolic and graphical representations into a single manipulable focus-i-context display and providing a small set of interactive operations (e.g. sorting), the Table Lens supports navigating around a large data space easily isolating and investigating interesting features and patterns. This high-bandwidth interactivity enables an extremely powerful style of direct manipulation exploratory data analysis.

Implementational Reflection in Silica

The value of computational reflection has been explored in a number of programming language efforts. The major claim of this paper is that an ostensibly broader view of reflection, which we call implementational reflection, can be applied to the design of other kinds of systems, accruing the same benefits that arise in the programming language case. The domain of window systems in general, and the Silica window system in particular are used to illustrate how reflection can be applied more broadly. Silica is a CLOS-based window system that is a part of the Common Lisp Interface Manager, an emerging user interface programming standard for Common Lisp.

Semi-structured messages are surprisingly useful for computer-supported coordination

This paper argues that using a set of semi-structured message templates is surprisingly helpful in designing a variety of computer-based communication and coordination systems. Semi-structured messages can help provide automatic aids for: (1) composing messages to be sent, (2) selecting, sorting, and prioritizing messages that are received, (3) responding automatically to some messages, and (4) suggesting likely responses to other messages. The use of these capabilities is illustrated in a range of applications including electronic mail, computer conferencing, calendar management, and task tracking. The applications show how ideas from artificial intelligence (such as inheritance and production rules) and ideas from user interface design (such as interactive graphical editors) can be combined in novel ways for dealing with semi-structured messages. The final part of the paper discusses how communities can evolve a useful set of message type definitions.