Browsing by Author "Hochheiser, Harry"
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Item An Augmented Visual Query Mechanism for Finding Patterns in Time Series Data(2002-09-18) Keogh, Eamonn; Hochheiser, Harry; Shneiderman, BenRelatively few query tools exist for data exploration and pattern identification in time series data sets. In previous work we introduced Timeboxes. Timeboxes are rectangular, direct-manipulation queries for studying time-series datasets. We demonstrated how Timeboxes can be used to support interactive exploration via dynamic queries, along with overviews of query results and drag-and-drop support for query-by-example. In this paper, we extend our work by introducing Variable Time Timeboxes (VTT). VTTs are a natural generalization of Timeboxes, which permit the specification of queries that allow a degree of uncertainty in the time axis. We carefully motivate the need for these more expressive queries, and demonstrate the utility of our approach on several data sets. (Also UMIACS-TR-2002-78) (Also HCI-TR-2002-15)Item An Augmented Visual Query Mechanism for Finding Patterns in Time Series Data (2002)(2005) Keogh, Eamonn; Hochheiser, Harry; Shneiderman, Ben; ISRRelatively few query tools exist for data exploration and pattern identification in time series data sets. In previous work we introduced Timeboxes. Timeboxes are rectangular, direct-manipulation queries for studying time-series datasets. We demonstrated how Timeboxes can be used to support interactive exploration via dynamic queries, along with overviews of query results and drag-and-drop support for query-by-example. In this paper, we extend our work by introducing Variable Time Timeboxes (VTT). VTTs are a natural generalization of Timeboxes, which permit the specification of queries that allow a degree of uncertainty in the time axis. We carefully motivate the need for these more expressive queries, and demonstrate the utility of our approach on several data sets.Item Coordinating Overviews and Detail Views of WWW Log Data (2000)(2005) Hochheiser, Harry; Shneiderman, Ben; ISRWeb server log analysis tools provide site operators with useful information regarding the visitors to their sites. Unfortunately, the utility of these tools is often limited by the use of aggregate summaries that hide the information associated with individual requests, and by the absence of contextual data that might help users interpret those summaries. Building upon earlier work in the use of starfield visualizations to display web site requests as individual data points [8], this paper describes the use of multiple-coordinated visualizations of web log data at varying granularities, and alongside additional related displays of appropriate contextual information.Item Dynamic query tools for time series data sets: Timebox widgets for interactive exploration (2004)(2005) Hochheiser, Harry; Shneiderman, Ben; ISRTimeboxes are rectangular widgets that can be used in direct-manipulation graphical user interfaces (GUIs) to specify query constraints on time series data sets. Timeboxes are used to specify simultaneously two sets of constraints: given a set of N time series profiles, a timebox covering time periods x1...x2 (x1rx2) and values y1...y2 (y1ry2) will retrieve only those nAN that have values y1ryry2 during all times x1rxrx2. TimeSearcher is an information visualization tool that combines timebox queries with overview displays, query-byexample facilities, and support for queries over multiple time-varying attributes. Query manipulation tools including pattern inversion and eaders & laggards graphical bookmarks provide additional support for interactive exploration of data sets. Extensions to the basic timebox model that provide additional expressivity include variable time timeboxes, which can be used to express queries with variability in the time interval, and angular queries, which search for ranges of differentials, rather than absolute values. Analysis of the algorithmic requirements for providing dynamic query performance for timebox queries showed that a sequential search outperformed searches based on geometric indices. Design studies helped identify the strengths and weaknesses of the query tools. Extended case studies involving the analysis of two different types of data from molecular biology experiments provided valuable feedback and validated the utility of both the timebox model and the TimeSearcher tool.Timesearcher is available [url=http://www.cs.umd.edu/hcil/ timesearcher]online.[/url]
Item Dynamic Querying for Pattern Identification in Microarray and Genomic Data (2003)(2005) Hochheiser, Harry; Baehrecke, Eric H.; Mount, Stephen M.; Shneiderman, Ben; ISRData sets involving linear ordered sequences are a recurring theme in bioinformatics. Dynamic query tools that support exploration of these data sets can be useful for identifying patterns of interest. This paper describes the use of one such tool TimeSearcher - to interactively explore linear sequence data sets taken from two bioinformatics problems. Microarray time course data sets involve expression levels for large numbers of genes over multiple time points. TimeSearcher can be used to interactively search these data sets for genes with expression profiles of interest. The occurrence frequencies of short sequences of DNA in aligned exons can be used to identify sequences that play a role in the pre-mRNA splicing. TimeSearcher can be used to search these data sets for candidate splicing signals.Item Performance Benefits of Simultaneous over Sequential Menus as Task Complexity Increases(1999) Hochheiser, Harry; Kositsyna, Natalya; Ville, G.; Shneiderman, B.; ISRTo date, experimental comparisons of menu layouts have concentrated on variants of hierarchical structures of sequentially presented menus. Simultaneous menus - layouts which present multiple active menus on a screen at the same time - are an alternative arrangement that may be useful in many web design situations.This paper describes an experiment involving a between-subject comparison of simultaneous menu and their traditional sequential counterparts. Twenty experienced web users used either simultaneous or sequential menus in a standard web browser to answer questions based on US Census data. For novice users performing simple tasks the simplicity of sequential menus appears to be helpful, but for most tasks and most users there is good evidence to believe that simultaneous menus speed performance and improve satisfaction. Design improvements can amplify the benefits of simultaneous menu layouts.
Item Understanding Patterns of User Visits to Web Sites: Interactive Starfield Visualizations of WWW Log Data(1999-02-05) Hochheiser, Harry; Shneiderman, BenHTTP server log files provide Web site operators with substantial detail regarding the visitors to their sites. Interest in interpreting this data has spawned an active market for software packages that summarize and analyze this data, providing histograms, pie graphs, and other charts summarizing usage patterns. While useful, these summaries obscure useful information and restrict users to passive interpretation of static displays. Interactive starfield visualizations can be used to provide users with greater abilities to interpret and explore web log data. By combining two-dimensional displays of thousands of individual access requests, color and size coding for additional attributes, and facilities for zooming and filtering, these visualizations provide capabilities for examining data that exceed those of traditional web log analysis tools. We introduce a series of interactive starfield visualizations, which can be used to explore server data across various dimensions. Possible uses of these visualizations are discussed, and difficulties of data collection, presentation, and interpretation are explored. (Also cross-referenced as UMIACS-99-11)Item Understanding Patterns of User Visits to Web Sites: Interactive Starfield Visualization of WWW Log Data(1999) Hochheiser, Harry; Shneiderman, Ben; ISRHTTP server log files provide Web site operators with substantial detail regarding the visitors to their sites. Interest in interpreting this data has spawned an active market for software packages that summarize and analyze this data, providing histograms, pie graphs, and other charts summarizing usage patterns. While useful, these summaries obscure useful information and restrict users to passive interpretation of static displays. Interactive starfield visualizations can be used to provide users with greater abilities to interpret and explore web log data. By combining two-dimensional displays of thousands of individual access requests, colorand size coding for additional attributes, and facilities for zooming andfiltering, these visualizations provide capabilities for examining data that exceed those of traditional web log analysis tools. We introduce a series of interactive starfield visualizations, which can be used to explore server data across various dimensions. Possible uses of these visualizations are discussed, and difficulties of data collection, presen-tation, and interpretation are explored.Item Universal Usability as a Stimulus to Advanced Interface Design (2001)(2005) Shneiderman, Ben; Hochheiser, Harry; ISRThe desire to make computing available to broader populations has historically been a motivation for research and innovation that led to new breakthroughs in usability. Menus, graphical user interfaces, and the World-Wide Web, are examples of innovative technological solutions that have arisen out of the challenge of bringing larger and more diverse groups of users into the world of computing. Universal usability is the latest such challenge: In order to build systems that are universally usable, designers must account for technology variety, user diversity, and gaps in user knowledge. These issues are particularly challenging and important in the context of increasing the usability of the World-Wide-Web. To raise awareness, we urge web designers to provide universal usability statements, to provide users with useful information about the usability of their sites. These statements can inform users and thereby reduce frustration and confusion. Further steps toward universal usability might be achieved through research aimed at developing tools that would encourage or promote usability. We close with five proposals for future research.Item Universal Usability statements: Marking the trail for all users(2003-01-21) Hochheiser, Harry; Shneiderman, BenSignposts at ski areas help skiers to choose slopes that match their skills and equipment. They describe easy, intermediate and expert trails, indicate which ones are groomed, and give their length or vertical drop. Skiers use this information to make informed decisions, avoiding routes that may be too difficult or too long. They may choose different skis or waxes depending on the conditions. For web surfers, good guidance and safe visits are still too rare. Despite extensive research and improved products, the primary experience of many users is frustration and anxiety. Common problems include long download times, incompatible browser versions, and unavailable plug-ins. Too often users find that their screen size does not match the designer's screen size, needed fonts are not installed, or media players just don't work on their machine. These problems are troubling to experienced users as well as novices and even more problematic to users with disabilities. However, web site designers can take immediate measures to help web surfers find safe trails and have more successful web experiences. Just as park rangers provide information that describes the terrain and the obstacles that may be lurking around the corner, web site designers can provide web versions of this information. When it becomes apparent that too many trails are marked as 'extremely difficult', thoughtful park rangers will recognize the need to cut some more 'moderate' and 'easy' trails to enable more visitors to enjoy the scenery. (UMIACS-TR-2001-84) (HCIL-TR-2001-02)Item Universal Usability Statements: Marking the Trail for All Users (2001)(2005) Hochheiser, Harry; Sheiderman, Ben; ISRSignposts at ski areas help skiers to choose slopes that match their skills and equipment. They describe easy, intermediate and expert trails, indicate which ones are groomed, and give their length or vertical drop. Skiers use this information to make informed decisions, avoiding routes that may be too difficult or too long. They may choose different skis or waxes depending on the conditions.Item Using Interactive Visualizations of WWW Log Data to Characterize Access Patterns and Inform Site Design(1999) Hochheiser, Harry; Shneiderman, Ben; ISRHTTP server log files provide Web site operators with substantial detail regarding the visitors to their sites. Interest ininterpreting this data has spawned an active market for software packages that summarize and analyze this data, providing histograms, pie graphs, and other charts summarizing usage patterns. While useful, these summaries obscureuseful information and restrict users to passive interpretation of static displays. Interactive visualizations can be used to provide users with greater abilities to interpret and explore web log data. Bycombining two-dimensional displays of thousands of individual access requests, color and size coding for additional attributes, and facilities for zooming and filtering, these visualizations provide capabilities for examining data that exceed those of traditional web log analysis tools.We introduce a series of interactive visualizations that can be used to explore server data across various dimensions. Sample visualizations of server data from two web sites are presented. Coordinated, snap-together visualizations (STVs) of log data are introduced as a means of gaining additional expressive power. Possible uses of these visualizations are discussed, and difficulties of data collection, presentation, and interpretation are explored.
Item Visual Queries for Finding Patterns in Time Series Data (2002)(2005) Hochheiser, Harry; Shneiderman, Ben; ISRFew tools exist for data exploration and pattern identification in time series data sets. Timeboxes are rectangular, direct-manipulation queries for studying time-series datasets. Timeboxes are the primary query tool in our Time- Searcher application, which supports interactive exploration via dynamic queries, along with overviews of query results and drag-and-drop support for query-by-example. This paper describes the TimeSearcher application and possible extensions to the timebox query model, along with a discussion of the use of TimeSearcher for exploring a time series data set involving gene expression profiles.Item Visual Specification of Queries for Finding Patterns in Time-Series Data (2001)(2005) Hochheiser, Harry; Shneiderman, Ben; ISRWidespread interest in discovering features and trends in time- series has generated a need for tools that support interactive exploration.This paper introduces timeboxes: a powerful graphical, directmanipulation metaphor for the specification of queries over time-series datasets. Our TimeFinder implementation of timeboxes supports interactive formulation and modification of queries, thus speeding the process of exploring time-series data sets and guiding data mining. TimeFinder includes windows for timebox queries, individual time-series, and details-on-demand. Other features include drag-and-drop support for query-by-example and graphical envelopes for displaying the extent of the entire data set and result set from a given query. Extensions involving increased expressive power and general temporal data sets are discussed.