72 research outputs found
Viewpoints: A high-performance high-dimensional exploratory data analysis tool
Scientific data sets continue to increase in both size and complexity. In the
past, dedicated graphics systems at supercomputing centers were required to
visualize large data sets, but as the price of commodity graphics hardware has
dropped and its capability has increased, it is now possible, in principle, to
view large complex data sets on a single workstation. To do this in practice,
an investigator will need software that is written to take advantage of the
relevant graphics hardware. The Viewpoints visualization package described
herein is an example of such software. Viewpoints is an interactive tool for
exploratory visual analysis of large, high-dimensional (multivariate) data. It
leverages the capabilities of modern graphics boards (GPUs) to run on a single
workstation or laptop. Viewpoints is minimalist: it attempts to do a small set
of useful things very well (or at least very quickly) in comparison with
similar packages today. Its basic feature set includes linked scatter plots
with brushing, dynamic histograms, normalization and outlier detection/removal.
Viewpoints was originally designed for astrophysicists, but it has since been
used in a variety of fields that range from astronomy, quantum chemistry, fluid
dynamics, machine learning, bioinformatics, and finance to information
technology server log mining. In this article, we describe the Viewpoints
package and show examples of its usage.Comment: 18 pages, 3 figures, PASP in press, this version corresponds more
closely to that to be publishe
Usability testing for improving interactive geovisualization techniques
Usability describes a productās fitness for use according to a set of predefined criteria.
Whatever the aim of the product, it should facilitate usersā tasks or enhance their performance
by providing appropriate analysis tools. In both cases, the main interest is to satisfy users in
terms of providing relevant functionality which they find fit for purpose. āTesting usability
means making sure that people can find and work with [a productās] functions to meet their
needsā (Dumas and Redish, 1999: 4). It is therefore concerned with establishing whether
people can use a product to complete their tasks with ease and at the same time help them
complete their jobs more effectively.
This document describes the findings of a usability study carried out on DecisionSite Map
Interaction Services (Map IS). DecisionSite, a product of Spotfire, Inc.,1 is an interactive
system for the visual and dynamic exploration of data designed for supporting decisionmaking.
The system was coupled to ArcExplorer (forming DecisionSite Map IS) to provide
limited GIS functionality (simple user interface, basic tools, and data management) and
support users of spatial data. Hence, this study set out to test the suitability of the coupling
between the two software components (DecisionSite and ArcExplorer) for the purpose of
exploring spatial data. The first section briefly discusses DecisionSiteās visualization
functionality. The second section describes the test goals, its design, the participants and data
used. The following section concentrates on the analysis of results, while the final section
discusses future areas of research and possible development
Improving Accessibility and Usability of Geo-referenced Statistical Data
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.
(UMIACS-TR-2003-37)
(HCIL-2003-11
Development of a geovisual analytics environment using parallel coordinates with applications to tropical cyclone trend analysis
A global transformation is being fueled by unprecedented growth in the quality, quantity, and number of different parameters in environmental data through the convergence of several technological advances in data collection and modeling. Although these data hold great potential for helping us understand many complex and, in some cases, life-threatening environmental processes, our ability to generate such data is far outpacing our ability to analyze it. In particular, conventional environmental data analysis tools are inadequate for coping with the size and complexity of these data. As a result, users are forced to reduce the problem in order to adapt to the capabilities of the tools. To overcome these limitations, we must complement the power of computational methods with human knowledge, flexible thinking, imagination, and our capacity for insight by developing visual analysis tools that distill information into the actionable criteria needed for enhanced decision support. In light of said challenges, we have integrated automated statistical analysis capabilities with a highly interactive, multivariate visualization interface to produce a promising approach for visual environmental data analysis. By combining advanced interaction techniques such as dynamic axis scaling, conjunctive parallel coordinates, statistical indicators, and aerial perspective shading, we provide an enhanced variant of the classical parallel coordinates plot. Furthermore, the system facilitates statistical processes such as stepwise linear regression and correlation analysis to assist in the identification and quantification of the most significant predictors for a particular dependent variable. These capabilities are combined into a unique geovisual analytics system that is demonstrated via a pedagogical case study and three North Atlantic tropical cyclone climate studies using a systematic workflow. In addition to revealing several significant associations between environmental observations and tropical cyclone activity, this research corroborates the notion that enhanced parallel coordinates coupled with statistical analysis can be used for more effective knowledge discovery and confirmation in complex, real-world data sets
Development of a geovisual analytics environment using parallel coordinates with applications to tropical cyclone trend analysis
A global transformation is being fueled by unprecedented growth in the quality, quantity, and number of different parameters in environmental data through the convergence of several technological advances in data collection and modeling. Although these data hold great potential for helping us understand many complex and, in some cases, life-threatening environmental processes, our ability to generate such data is far outpacing our ability to analyze it. In particular, conventional environmental data analysis tools are inadequate for coping with the size and complexity of these data. As a result, users are forced to reduce the problem in order to adapt to the capabilities of the tools. To overcome these limitations, we must complement the power of computational methods with human knowledge, flexible thinking, imagination, and our capacity for insight by developing visual analysis tools that distill information into the actionable criteria needed for enhanced decision support. In light of said challenges, we have integrated automated statistical analysis capabilities with a highly interactive, multivariate visualization interface to produce a promising approach for visual environmental data analysis. By combining advanced interaction techniques such as dynamic axis scaling, conjunctive parallel coordinates, statistical indicators, and aerial perspective shading, we provide an enhanced variant of the classical parallel coordinates plot. Furthermore, the system facilitates statistical processes such as stepwise linear regression and correlation analysis to assist in the identification and quantification of the most significant predictors for a particular dependent variable. These capabilities are combined into a unique geovisual analytics system that is demonstrated via a pedagogical case study and three North Atlantic tropical cyclone climate studies using a systematic workflow. In addition to revealing several significant associations between environmental observations and tropical cyclone activity, this research corroborates the notion that enhanced parallel coordinates coupled with statistical analysis can be used for more effective knowledge discovery and confirmation in complex, real-world data sets
Preview Cues: Enhancing Access to Multimedia Content
We describe preview cues, a lightweight mechanism to assist exploration of multimedia content. A preview cue provides a preview of the kind of content/information associated with an area (as opposed to an instance) of a domain. Preview cues associate media files and their meta data with the label of a topic in a domain. A lightweight gesture such as brushing a cursor over a label initiates playback of the preview cue file associated with that label. With these cues, users can preview the type of content associated with an area of a domain in order to decide whether or not that area is of interest for further exploration before having to select it. In this paper we describe the preview cues mechanism. We look at one case study of an implementation of preview cues in the audio domain, and we present the results of a user study of preview cue deployment. We conclude with a discussion of issues for future research
The TOP-Slider for Multi-criteria Decision Making by Non-Specialists
International audienc
A Formalism for Visual Query Interface Design
The massive volumes and the huge variety of large knowledge bases make information
exploration and analysis difficult. An important activity is data filtering and
selection, in which both querying and visualization play important roles. Interfaces for data exploration environments normally include both, integrating them as tightly as possible.
But many features of information exploration environments, such as visual representation
of queries, visualization of query results, interactive data selection from visualizations, have only been studied separately. The intrinsic connections between
them have not been described formally. The lack of formal descriptions inhibits the
development of techniques that produce new representations for queries, and natural
integration of visual query specification with query result visualization.
This thesis describes a formalism that describes the basic components of information
exploration and and their relationships in information exploration environments. The key aspect of the formalism is that it unifies querying and visualization within a single framework, which provides a foundation for designing and analysing visual query
interfaces.
Various innovative designs of visual query representations can be derived from the
formalism. Simply comparing them with existing ones is not enough, it is more important to discover why one visual representation is better or worse than another. To do this it is necessary to understand usersā cognitive activities, and to know how these cognitive activities are enhanced or inhibited by different presentations of a query so that novel interfaces can be created and improved based on user testing.
This thesis presents a new experimental methodology for evaluating query representations, which uses stimulus onset asynchrony to separate different aspects of query comprehension. This methodology was used to evaluate a new visual query representation based on Karnaugh maps, and showing that there are two qualitatively different approaches to comprehension: deductive and inductive. The Karnaugh map representation scales extremely well with query complexity, and the experiment shows that its good scaling properties occur because it strongly facilitates inductive comprehension
Visual Systems for Interactive Exploration and Mining of Large-Scale Neuroimaging Data Archives
While technological advancements in neuroimaging scanner engineering have improved the efficiency of data acquisition, electronic data capture methods will likewise significantly expedite the populating of large-scale neuroimaging databases. As they do and these archives grow in size, a particular challenge lies in examining and interacting with the information that these resources contain through the development of compelling, user-driven approaches for data exploration and mining. In this article, we introduce the informatics visualization for neuroimaging (INVIZIAN) framework for the graphical rendering of, and dynamic interaction with the contents of large-scale neuroimaging data sets. We describe the rationale behind INVIZIAN, detail its development, and demonstrate its usage in examining a collection of over 900 T1-anatomical magnetic resonance imaging (MRI) image volumes from across a diverse set of clinical neuroimaging studies drawn from a leading neuroimaging database. Using a collection of cortical surface metrics and means for examining brain similarity, INVIZIAN graphically displays brain surfaces as points in a coordinate space and enables classification of clusters of neuroanatomically similar MRI images and data mining. As an initial step toward addressing the need for such user-friendly tools, INVIZIAN provides a highly unique means to interact with large quantities of electronic brain imaging archives in ways suitable for hypothesis generation and data mining
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