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.Plaisant, Catherine

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Now showing 1 - 10 of 24
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    Representing Unevenly-Spaced Time Series Data for Visualization and Interactive Exploration (2005)
    (2005) Aris, Aleks; Shneiderman, Ben; Plaisant, Catherine; Shmueli, Galit; Jank, Wolfgang; ISR
    Visualizing time series data is useful to support discovery of relations and patterns in financial, genomic, medical and other applications. In most time series, measurements are equally spaced over time. This paper discusses the challenges for unevenly-spaced time series data and presents four methods to represent them: sampled events, aggregated sampled events, event index and interleaved event index. We developed these methods while studying eBay auction data with TimeSearcher. We describe the advantages, disadvantages, choices for algorithms and parameters, and compare the different methods. Since each method has its advantages, this paper provides guidance for choosing the right combination of methods, algorithms, and parameters to solve a given problem for unevenly-spaced time series. Interaction issues such as screen resolution, response time for dynamic queries, and meaning of the visual display are governed by these decisions.
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    Show Me! Guidelines for Producing Recorded Demonstrations (2005)
    (2005) Plaisant, Catherine; Shneiderman, Ben; ISR
    Although recorded demonstrations (screen capture animations with narration) have become a popular form of instruction for user interfaces, little work has been done to describe guidelines for their design. Based on our experience in several projects, we offer a starting set of guidelines for the design of recorded demonstrations. Technical guidelines encourage users to keep file sizes small, strive for universal usability, and ensure user control etc. and provide tips to achieve those goals. Content guidelines include: create short demonstrations that focus on tasks, highlight each step with auditory and visual cues, synchronize narration and animation carefully, and create demonstrations with a clear beginning, middle, and end.
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    New Approaches to Help Users Get Started with Visual Interfaces: Multi-Layered Interfaces and Integrated Initial Guidance (2003)
    (2005) Kang, Hyunmo; Plaisant, Catherine; Shneiderman, Ben; ISR
    We are investigating new ways to help users learn to use public access interactive tools, in particular for the visual exploration of government statistics. Our work led to a series of interfaces using multi-layered design and a new help method called Integrated Initial Guidance. Multi-layer designs structure an interface so that a simpler interface is available for users to get started and more complex features are accessed as users move through the more advanced layers. Integrated Initial Guidance provides help within the working interface, right at the start of the application. Using the metaphor of ticky notes overlaid on top of the functional interface locates the main widgets, demonstrates their manipulation, and explains the resulting actions using preset animation of the interface. Additional sticky notes lead to example tasks, also being executed step by step within the interface itself. Usability testing with 12 participants led to refined designs and guidelines for the design of Integrated Initial Guidance interfaces.
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     Hear the PatternInteractive Sonification of Geographical Data Patterns (2004)
    (2005) Zhao, Haixia; Plaisant, Catherine; Shneiderman, Ben; ISR
    In this paper we describe our investigation of using interactive sonification (non-speech sound) to present the geographical distribution pattern of statistical data to vision impaired users. We first discuss the design space in the dimensions of interaction actions, data representation forms, input devices, navigation structures, and sound feedback encoding. Two interfaces have been designed according to the design space, one using a keyboard and another using a smooth surface touch tablet. A study with three blind users shows that they are able to perceive patterns of 5-category values on both familiar and unknown maps, and learn new map geography, in both interfaces.
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    Toward a Statistical Knowledge Network (2004)
    (2005) Marchionini, Gary; Haas, Stephanie; Plaisant, Catherine; Shneiderman, Ben; Hert, Carol; ISR
    Statistics support planning and decision making and enormous efforts are made to collect data and produce statistics at all levels of governance. An important principle of democratic societies is that government statistics should be accessible to the broadest possible constituencies to empower better plans and decisions in all aspects of life. Given the potential of near-ubiquitous Internet access in homes and workplaces and efforts by government agencies to mount websites, physical access to large volumes of government is close to a fait accompli. What remains a significant challenge is enabling access to the right statistical information at the right time and in the right form.
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    Interactive Pattern Search in Time Series (2004)
    (2005) Buono, Paolo; Aris, Aleks; Plaisant, Catherine; Khella, Amir; Shneiderman, Ben; ISR
    The need for pattern discovery in long time series data led researchers to develop algorithms for similarity search. Most of the literature about time series focuses on algorithms that index time series and bring the data into the main storage, thus providing fast information retrieval on large time series. This paper reviews the state of the art in visualizing time series, and focuses on techniques that enable users to interactively query time series. Then it presents TimeSearcher 2, a tool that enables users to explore multidimensional data using coordinated tables and graphs with overview+detail, filter the time series data to reduce the scope of the search, select an existing pattern to find similar occurrences, and interactively adjust similarity parameters to narrow the result set. This tool is an extension of previous work, TimeSearcher 1, which uses graphical timeboxes to interactively query time series data.
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    Listening to Maps: User Evaluation of Interactive Sonifications of Geo-Referenced Data (2004)
    (2005) Zhao, Haixia; Smith, Benjamin K.; Norman, Kent L.; Plaisant, Catherine; Shneiderman, Ben; ISR
    In this paper, we summarize the Auditory Information Seeking Principle (AISP) (gist, navigate, filter, and details-ondemand). To improve blind access to geo-referenced statistical data, we developed several interactive sonifications, adhering to the above AISP. Two user studies are presented. In the first user study with nine sighted subjects, a preliminary map design is compared with an enhanced table design. The study shows subjects can recognize geographic data distribution patterns on a real map with 51 geographic regions, in both designs. The map-based design was strongly preferred. The study also shows evidence that AISP conforms to people information seeking strategies. Based on the observations from the first user study, a second user study was conducted with forty-eight sighted subjects comparing four map designs. The effects of using sound to encode vertical geographic positions and two map navigation methods were compared. The result is presented and future work is discussed.
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    Extending the Utility of Treemaps with Flexible Hierarchy (2004)
    (2005) Chintalapani, Gouthami; Plaisant, Catherine; Shneiderman, Ben; ISR
    Treemaps is a visualization technique for presenting hierarchical information on two dimensional displays. Prior implementations limit the visualization to pre-defined static hierarchies. Flexible hierarchy, a new capability of Treemap 4.0, enables users to define various hierarchies through dynamically selecting a series of data attributes so that they can discover patterns, clusters and outliers. This paper describes the design and implementation issues of flexible hierarchy. It then reports on a usability study which led to enhancements to the interface.
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    Immediate Usability: A Case Study of Public Access Design for a Community Photo Library (2003)
    (2005) Kules, Bill; Kang, Hyunmo; Plaisant, Catherine; Rose, Anne; Shneiderman, Ben; ISR
    This paper describes a novel instantiation of a digital photo library in a public access system. It demonstrates how designers can utilize characteristics of a target user community (social constraints, trust, and a lack of anonymity) to provide capabilities that would be impractical in other types of public access systems. It also presents a compact set of design principles and guidelines for ensuring the immediate usability of public access information systems. These principles and guidelines were derived from our experience developing PhotoFinder Kiosk, a community photo library. Attendees of a major HCI conference (CHI 2001 Conference on Human Factors in Computing Systems) successfully used the tool to browse and annotate collections of photographs spanning 20 years of HCI-related conferences, producing a richly annotated photo history of the field of human-computer interaction. Observations and log data were used to evaluate the tool and develop the guidelines. They provide specific guidance for practitioners, as well as a useful framework for additional research in public access interfaces.
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    Improving Accessibility and Usability of Geo-referenced Statistical Data (2003)
    (2005) Zhao, Haixia; Plaisant, Catherine; Shneiderman, Ben; ISR
    Several technology breakthroughs are needed to achieve the goals of universal accessibility and usability. These goals are especially challenging in the case of geo-referenced statistical data that many U.S. government agencies supply. We present technical and user-interface design challenges in accommodating users with low-end technology (slow network connection and low-end machine) and users who are blind or vision-impaired. Our solutions are presented and future work is discussed.