George Chin

The development of cooperation: five years of participatory design in the virtual school

During the past five years, our research group worked with a group of public school teachers to define, develop, and assess network-based support for collaborative learning in middle school physical science and high school physics. From the outset, we committed to a participatory design approach. This design collaboration has now existed far longer than is typical of participatory design endeavors, particularly in North America. The nature of our interactions, and in particular the nature of the role played by the teachers has changed significantly through the course of the project. We suggest that there may be a long-term developmental unfolding of roles and relationships in participatory design.

Requirements development in scenario-based design

We describe and analyze the process of requirements development in scenario based design through consideration of a case study. In our project, a group of teachers and system developers initially set out to create a virtual physics laboratory. Our design work centered on the collaborative development of a series of scenarios describing current and future classroom activities. We observed classroom scenarios to assess needs and opportunities, and envisioned future scenarios to specify and analyze possible design moves. We employed claims analysis to evaluate design trade-offs implicit in these scenarios, to codify the specific advantages and disadvantages in achieving requirements. Through the course of this process, the nature of our project requirements has evolved, providing more information but also more kinds of information. We discuss the utility of managing requirements development through an evolving set of scenarios, and the generality of the scenario stages from this case study.

Participatory analysis: shared development of requirements from scenarios

Participatory design typically focuses on envisionment and evaluation activities. We explored a method for pushing the participatory activities further “upstream” in the design process, to the initial analysis of requirements. We used a variant of the task-artifact fi-arnework, carrying out a participatory claims analysis during a design workshop fm a project addressing collaborative science education. The analysis used videotaped classroom sessions as source material. The participant-teachers were highly engaged by the analysis process and contributed significantly to the analysis results. We conclude that the method has promise as a technique for evoking self-reflection and analysis in a participatory design setting.

Exploring the analytical processes of intelligence analysts

We present an observational case study in which we investigate and analyze the analytical processes of intelligence analysts. Participating analysts in the study carry out two scenarios where they organize and triage information, conduct intelligence analysis, report results, and collaborate with one another. Through a combination of scenario-based analysis, artifact analysis, role-playing, interviews, and participant observations, we explore the space and boundaries in which intelligence analysts work and operate. We also assess the implications of our findings on the use and application of key information technologies.

A Novel Visualization Technique for Electric Power Grid Analytics

The application of information visualization holds tremendous promise for the electric power industry, but its potential has so far not been sufficiently exploited by the visualization community. Prior work on visualizing electric power systems has been limited to depicting raw or processed information on top of a geographic layout. Little effort has been devoted to visualizing the physics of the power grids, which ultimately determines the condition and stability of the electricity infrastructure. Based on this assessment, we developed a novel visualization system prototype, GreenGrid, to explore the planning and monitoring of the North American Electricity Infrastructure. The paper discusses the rationale underlying the GreenGrid design, describes its implementation and performance details, and assesses its strengths and weaknesses against the current geographic-based power grid visualization. We also present a case study using GreenGrid to analyze the information collected moments before the last major electric blackout in the Western United States and Canada, and a usability study to evaluate the practical significance of our design in simulated real-life situations. Our result indicates that many of the disturbance characteristics can be readily identified with the proper form of visualization.

Graph Signatures for Visual Analytics

We present a visual analytics technique to explore graphs using the concept of a data signature. A data signature, in our context, is a multidimensional vector that captures the local topology information surrounding each graph node. Signature vectors extracted from a graph are projected onto a low-dimensional scatterplot through the use of scaling. The resultant scatterplot, which reflects the similarities of the vectors, allows analysts to examine the graph structures and their corresponding real-life interpretations through repeated use of brushing and linking between the two visualizations. The interpretation of the graph structures is based on the outcomes of multiple participatory analysis sessions with intelligence analysts conducted by the authors at the Pacific Northwest National Laboratory. The paper first uses three public domain data sets with either well-known or obvious features to explain the rationale of our design and illustrate its results. More advanced examples are then used in a customized usability study to evaluate the effectiveness and efficiency of our approach. The study results reveal not only the limitations and weaknesses of the traditional approach based solely on graph visualization, but also the advantages and strengths of our signature-guided approach presented in the paper

New paradigms in problem solving environments for scientific computing

Computer and computational scientists at Pacific Northwest National Laboratory (PNNL) are studying and designing collaborative problem solving environments (CPSEs) for scientific computing in various domains. Where most scientific computing efforts focus at the level of the scientific codes, file systems, data archives, and networked computers, our analysis and design efforts are aimed at developing enabling technologies that are directly meaningful and relevant to domain scientist at the level of the practice and the science. We seek to characterize the nature of scientific problem solving and look for innovative ways to improve it. Moreover, we aim to glimpse beyond current systems and technical limitations to derive a design that expresses the scientists own perspective on research activities, processes, and resources. The product of our analysis and design work is a conceptual scientific CPSE prototype that specifies a complete simulation and modeling user environment and a suite of high-level problem solving tools.

Evaluating the potential of multithreaded platforms for irregular scientific computations

The resurgence of current and upcoming multithreaded architectures and programming models led us to conduct a detailed study to understand the potential of these platforms to increase the performance of data-intensive, irregular scientific applications. Our study is based on a power system state estimation application and a novel anomaly detection application applied to network traffic data. We also conducted a detailed evaluation of the platforms using microbenchmarks in order to gain insight into their architectural capabilities and their interaction with programming models and application software. The evaluation was performed on the Cray MTA-2 and the Sun Niagar.

Articulating collaboration in a learning community

A common computer-based collaborative learning approach is to simply introduce contemporary computermediated communication technology into the classroom to support prescribed learning activities. This approach assumes that all students collaborate in similar ways and that presentday technology is sufficient to accommodate all collaboration forms. This view is superficial and limiting. Students collaborate in different ways at different levels on different learning activities. A more detailed articulation of collaboration in learning is crucial to understanding and extending the pedagogical capabilities and usefulness of collaborative technologies. A model is presented for a more finely articulated form of analysis that enumerates types of collaborative learning activities and evaluates how these activities may be supported through different design options. The analysis is based on actual classroom scenarios and the collaboration requirements that emerge from them. The authors have successfully applied this analysis model in the design of a computer-based collaborative learning environment for science education.

Generating Graphs for Visual Analytics through Interactive Sketching

We introduce an interactive graph generator, GreenSketch, designed to facilitate the creation of descriptive graphs required for different visual analytics tasks. The human-centric design approach of GreenSketch enables users to master the creation process without specific training or prior knowledge of graph model theory. The customized user interface encourages users to gain insight into the connection between the compact matrix representation and the topology of a graph layout when they sketch their graphs. Both the human-enforced and machine-generated randomnesses supported by GreenSketch provide the flexibility needed to address the uncertainty factor in many analytical tasks. This paper describes more than two dozen examples that cover a wide variety of graph creations from a single line of nodes to a real-life small-world network that describes a snapshot of telephone connections. While the discussion focuses mainly on the design of GreenSketch, we include a case study that applies the technology in a visual analytics environment and a usability study that evaluates the strengths and weaknesses of our design approach