Institute for Systems Research Technical Reports

Permanent URI for this collectionhttp://hdl.handle.net/1903/4376

This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.

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Author: search.filters.author.Shneiderman, B.Subject: search.filters.subject.Systems Integration

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Now showing 1 - 6 of 6
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    Using Treemaps to Visualize the Analytic Hierarchy Process
    (1994) Asahi, Toshiyuki; Turo, D.; Shneiderman, B.; ISR
    Treemaps, a visualization method for large hierarchical data spaces, are used to augment the capabilities of the Analytic Hierarchy Process (AHP) for decision-making. Two direct manipulation tools, presented metamorphically as a "pump" and a "hook", were developed and applied to the treemap to support AHP sensitivity analysis. A usability study was conducted using a prototype AHP application; results showed that treemap representation of decision-support tools was acceptable for AHP users from both a visualization and data operation standpoint. Subjective preferences were high for AHP treemaps.
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    User Controlled Smooth Zooming for Information Visualization
    (1994) Jog, Ninog; Shneiderman, B.; ISR
    This paper discusses the design and implementation of user controlled smooth zooming of a starfield display. A starfield display is a two dimensional graphical visualization of a multidimensional database where every item from the database is represented as a small colored rectangle whose position is determined by its ranking along ordinal attributes of the items laid out on the axes. One way of navigating this visual information is by using a zooming tool to incrementally zoom in on the items by varying the attribute range on either axis independently - such zooming causes the rectangles to move continuously and to grow or shrink. To get a feeling of flying through the data, users should be able to track the motion of each rectangle without getting distracted by flicker or large jumps - conditions that necessitate high display refresh rates and closely spaced rectangles on successive frames. Although the use of high-speed hardware can achieve the required visual effect for small databases, the twin software bottlenecks of rapidly accessing display items and constructing a new display image fundamentally retard the refresh rate. Our work explores several methods to overcome these bottlenecks, presents a taxonomy of various zooming methods and introduces a new widget, the zoom bar, that facilitates zooming.

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    The Alphaslider: A Compact and Rapid Selector
    (1993) Ahlberg, Christopher; Shneiderman, B.; ISR
    Research has suggested that rapid, serial, visual presentation of text (RSVP) may be an effective way to scan and search through lists of text strings in search of words, names, etc. The Alphaslider widget employs RSVP as a method for rapidly scanning and searching lists or menus in a graphical user interface environment. The Alphaslider only uses an area less than 7 x 2.5 cm2. The tiny size of the Alphaslider allows it to be placed on a credit card, on a control panel for a VCR, or as a widget in a direct manipulation based database interface. an experiment was conducted with four Alphaslider designs which showed that novice Alphaslider users could locate one item in a list of 10,000 film titles in 24 seconds on average, an expert user in about 13 seconds.
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    Visual Information Seeking: Tight Coupling of Dynamic Query Filters with Starfield Displays
    (1993) Ahlberg, Christopher; Shneiderman, B.; ISR
    This paper offers new principles for visual information seeking (VIS). A key concept is to support browsing, which is distinguished from familiar query composition and information retrieval because of its emphasis on rapid filtering to reduce result sets, progressive refinement of search parameters, continuous reformulation of goals, and visual scanning to identify results. VIS principles developed include: dynamic query filters (query parameters are rapidly adjusted with sliders, buttons, maps, etc.), starfield displays (two- dimensional scatterplots to structure result sets and zooming to reduce clutter), and tight coupling (interrelating query components to preserve display invariants and support progressive refinement combined with an emphasis on using search output to foster search input). A FilmFinder prototype using movie database demonstrates these principles in a VIS environment.
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    Alpha Slider: Searching Textual Lists with Sliders
    (1993) Osada, M.; Liao, Holmes; Shneiderman, B.; ISR
    AlphaSlider is a query interface that uses a direct manipulation slider to select words, phrases, or names from an existing list. This paper introduces a prototype of AlphaSlider, describes the design issues, reports on an experimental evaluation, and offers directions for further research. The experiment tested 24 subjects selecting items from lists of 40, 80, 160, and 320 entries. Mean selection times only doubled with the 8-fold increase in list length. Users quickly accommodated to this selection method.
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    Dynamic Queries: A step Beyond Database Languages
    (1993) Shneiderman, B.; ISR
    The capacity to incrementally adjust a query (with sliders, buttons, selections from a set of discrete attribute values, etc.) coupled with a visual display of results that are rapidly updated, dramatically changes the information seeking process. Dynamic queries on the chemical table of elements, computer directions, and a real estate database were built and tested in three separate exploratory experiments. Preliminary results show highly significant performance improvements and user enthusiasm more commonly seen with video games. Widespread application seems possible but research issues abound in the areas of: (1) graphic visualization design, (2) database and display algorithms, and (3) user interface requirements. Challenges include methods for rapidly displaying and changing many points, colors, and areas; multi-dimensional pointing and exploring using 6 degree of freedom input/output devices; incorporation of sound and visual display techniques that increase user comprehension; and integration with existing database systems.