Institute for Systems Research

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Author: search.filters.author.Plaisant, C.Subject: search.filters.subject.human-computer interaction

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    Query Previews in Networked Information Systems
    (1995) Doan, Khoa; Plaisant, C.; Shneiderman, B.; ISR; CSHCN
    In a networked information system, there are three major obstacles facing users in a querying process: network performance, data volume and data complexity. In order to overcome these obstacles, we propose a two-phase approach of dynamic query formulation by volume preview. The two phases are the Query Preview andQuery Refinement. In the Query Preview phase, users formulate an initial query by selecting desired attribute values. The volume of matching data sets is shown graphically on Query bars which aid users to rapidly eliminate undesired data sets, and focus on a manageable number of relevant data sets. Query previews also prevent wasted steps by eliminating zero-hit queries. When the estimated number of data sets is low enough, the initial query is submitted to the network, which returns the metadata of the data sets for further refinement in the Query Refinement phase. The two-phase approach to query formulation overcomes slow network performance, and reduces the data volume and data complexity problems. This approach is especially appropriate for users who prefer the exploratory method to discover data patterns and exceptions during the query formulation process. Using this approach, we have developed dynamic query user interfaces to allow users to formulate their queries across a networked environment.
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    Browsing Hierarchical Data with Multi-Level Dynamic Queries and Pruning
    (1995) Kumar, Harsha P.; Plaisant, C.; Shneiderman, B.; ISR; CSHCN
    User often must browse hierarchies with thousands of nodes in search of those that best match their information needs. The PDQ Tree-browser (Pruning with Dynamic Queries) visualization tool was specified, designed and developed for this purpose. This tool presents trees in two tightly-coupled views, one a detailed view and the other an overview. Users can use dynamic queries, a method for rapidly filtering data, to filter nodes at each level of the tree. The dynamic query panels are user-customizable. Subtrees of unselected nodes are pruned out, leading to compact views of relevant nodes. Usability testing of the PDQ Tree- browser, done with 8 subjects, helped asses strengths and identify possible improvement. The PDQ Tree-browser was used in Network Management (600 nodes) and University Finder (1100 nodes) applications. A controlled experiment, with 24 subjects, showed that pruning significantly improved performance speed and subjective user satisfaction. Future research directions are suggested.
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    User Controlled Overviews of an Image Library: A Case Study of the Visible Human
    (1995) North, C.; Shneiderman, B.; Plaisant, C.; ISR
    This paper proposes a user interface for remote access of the National Library of Medicine's Visible Human digital image library. Users can visualize the library, browse contents, locate data of interest, and retrieve desired images. The interface presents a pair of tightly coupled views into the library data. The overview image provides a global view of the overall search space, and the preview image provides details about high resolution images available for retrieval. To explore, the user sweeps the views through the search space and receives smooth, rapid, visual feedback of contents. Desired images are automatically downloaded over the Internet from the library. Library contents are indexed by meta-data consisting of automatically generated miniature visuals. The interface software is completely functional and freely available for public use at: http://www.nlm.nih.gov/.
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    LifeLines: Visualizing Personal Histories
    (1995) Plaisant, C.; Milash, Brett; Rose, A.; Widoff, S.; Shneiderman, B.; ISR
    LifeLines provide a general visualization environment for personal histories that can be applied to medical and court records, professional histories and other types of biographical data. A one-screen overview shows multiple facets of the records. Aspects, for example medical conditions or legal cases, are displayed as individual time lines, while icons indicate discrete events, such as physician consultations or legal reviews. Line color and thickness illustrate relationships or significance, scaling tools and filters allow users to focus on part of the information. LifeLines reduce the chances of missing information, facilitate spotting anomalies and trends and streamline access to details, while remaining tailorable and easily sharable between applications. The paper describes the use of LifeLines for youth records of the Maryland Department of Juvenile Justice and also for medical records. User's feedback was collected using a Visual Basic Prototype for the youth record. Techniques to deal with complex records are reviewed and issues of a standard personal record format are discussed.