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, BenSubject: search.filters.subject.human computer interaction

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    User Interfaces for a Complex Robotic Task: A Comparison of Tiles vs. Overlapped Windows
    (1997) Lane, J. Corde; Kuester, Steven P.; Shneiderman, Ben; ISR
    High complexity tasks, such as remote teleoperation of robotic vehicles, often require multiple windows. For these complex tasks, the windows necessary for task completion, may occupy more area than available on a single visual display unit (VDU). Since the focus of the robotic task constantly changes, modular control panels that can be opened, closed, and moved on the screen are invaluable to the operator. This study describes a specific robotic task and the need for a multi window interface that can be easily manipulated. This paper examines two multi-window management strategies: tiled (fixed size) and arbitrary overlap. Multi-window searches were performed using the two management styles and they were compared on the basis of search completion time and error rates. Results with 35 novice users showed faster completion times for the tiled management strategy than for the arbitrary overlap strategy. Over factors such as the number of windows available, the number of displayed windows workload of opening or closing windows, and effect of learning are discussed.
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    Design and Evaluation of Incremental Data Structures and Algorithms for Dynamic Query Interfaces
    (1997) Tanin, Egemen; Beigel, Richard; Shneiderman, Ben; ISR
    Dynamic query interfaces (DQI) are a recently developed database access mechanism that provides continuous real-time feedback to the user during query formulation. Previous work shows that DQI are an elegant and powerful interface to small databases. Unfortunately, when applied to large databases, previous DQI algorithms slow to a crawl. We present a new incremental approach to DQI algorithms that works well with large databases, both in theory and in practice.
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    Data Structures for Dynamic Queries: An Analytical and Experimental Evaluation
    (1994) Jain, Vinit; Shneiderman, Ben; ISR
    Dynamic Queries is a querying technique for doing range search on multi-key data sets. It is a direct manipulation mechanism where the query is formulated using graphical widgets and the result s are displayed graphically preferably within 100 milliseconds.

    This paper evaluates four data structures, the multilist, the grid file, k-d tree and the quad tree used to organize data in high speed storage for dynamic queries. The effect of factors like size, distribution and dimensionality of data on the storage overhead and the speed of search is explored. Analytical models for estimating the storage and the search overheads are presented, and verified to be correct by empirical data. Results indicate that multilists are suitable for small (few thousand points) data sets irrespective of the data distribution. For large data sets the grid files are excellent for uniformly distributed data, and trees are good for skewed data distributions. There was no significant difference in performance between the tree structures.