Novel SVG Visualizations for Exploring Distributed Digital Libraries

Qianyi Gu, Faisal Ahmad, Tamara Sumner

Francis Molina

Department of Computer Science Project 2061
University of Colorado,Campus Box 430 American Association for the Advancement of Science
Boulder, CO, USA 80309-0430 1200 New York Avenue, NW, Washington DC, USA 20005


The Strand Map Service (SMS) provides educators and learners with conceptual browsing interfaces (CBI) that help them to locate and use learning resources in educational digital libraries [1] . The CBIs are constructed based on nationally recognized education standards. Their graphical representations help learners and educators to understand the learning objects and their internal relationships. To achieve these learning goals, the user needs to retrieve educational resources aligned to those objects and use the resources effectively. We have introduced a system that dynamically generates visualizations of these interfaces using SVG [2] . Because of its versatility, SVG has proved to be the ideal format for the SMS. In this paper, we will show our subsequent work on:

  1. How the CBI presents different views of the concept space to meet users’requests and different service scenarios—i.e., generation of novel visualizations from the same data repository.
  2. How the CBI integrates with different web services to help the users retrieve educational resources from distributed digital libraries.

Novel Visualization

Different use scenarios and tasks present different concerns and constraints to users of educational resources in digital libraries, necessitating information to be presented in a variety of perspectives. To fulfill these requirements, the service described in this paper introduces a methodology for generating novel visualizations based on the same information space. For example, a "nearest-neighbor" visualization (Figure 1), is generated to present information related to a targeted concept whose related ideas originate from different strand maps.

Figure 1: Example of novel visualization. A "nearest-neighbor" request returns the targeted concept, along with immediately related ideas from the information space regardless of map origin.

Web Services Integration

Our study [3] of the cognitive process has shown that the user can more easily form search requests on web-based educational resources by browsing and interacting with visual interfaces. The conceptual browsing interfaces that we are developing have dual use: 1) to help users understand the learning objects and their relationships by providing visualizations; and 2) to facilitate the formulation of search requests for educational resources related to learning goals and the retrieval of these resources from distributed digital libraries.

For forming search requests and retrieving resources, the visual interfaces serve as a single, unified gateway for users to explore distributed resources. By interacting exclusively with our visual interfaces, the user can search directly or indirectly for distributed web resources residing in different digital libraries such as the National Science Digital Library (NSDL), the Digital Library for Earth Science Education (DLESE), the Harvard-Smithsonian Digital Video Library (HSDVL) and even in a larger domain such as Google. The retrieval process is automatically handled by services provided through the visual interfaces. Instead of forming separate search queries on different digital libraries, the user only needs to interact with the learning goals found on our visual interfaces, an approach that is very similar to "federated searching". To achieve this goal, we bind our SVG visual interfaces to web services provided by various digital libraries. We will present more technical details of this integration and the results and analysis of the retrieval. Figure 2 shows an example of visual interfaces that give search results from different digital libraries for a specific learning object.

Figure 2: Example of retrieval result. Resources related to the learning object, "Water can be a liquid or a solid ... " are retrieved from four sources: the NSDL, HSDVL, DLESE, and Google.


Tamara Sumner, Faisal Ahmad, Sonal Bhushan, Qianyi Gu, Francis Molina, Stedman Willard, Michael Wright, Lynne Davis, and Greg Janée, "A Web Service Interface for Creating Concept Browsing Interfaces" D-Lib Magazine, November 2004, Volume 10 Number 11
Qianyi Gu, Faisal Ahmad, Francis Molina, Tamara Sumner, "Dynamically Generating Conceptual Browsing Interfaces for Digital Libraries Using SVG", 3rd Annual Conference on Scalable Vector Graphics, Tokyo, Japan · Sept 7-10, 2004
Bhushan, S., Language for describing digital library components. Masters Thesis, Department of Computer Science, University of Colorado at Boulder, 2004.

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