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A multi agency research initiative in digital libraries focuses on creating technologies required to manage future globally distributed information systems. Issues of primary interest are: interoperability, management of large and complex information spaces, and support for effective user interaction with large, distributed information systems. Research in digital libraries explores critical issues in the development and use of large scale networked knowledge repositories. The goals are to efficiently capture, store, organize, search, process, and retrieve knowledge from electronic collections containing text, images, maps, audio recordings, video and film clips, and the combinations thereof (multimedia). Conceptually, a digital library is analogous to a traditional library in the diversity and complexity of its collection. A single digital library contains many terabytes of information, distributed throughout the world. Digital libraries are designed to be used by a broad spectrum of the population -- not only scholars and researchers, but educators, students, and the general public. By developing digital libraries, many of the limitations and disadvantages associated with managing and using physical collections can be overcome. |
One information intensive challenge of digital libraries is semantic interoperability -- the ability to search for a topic across multiple sources that use different vocabularies. Such interoperability takes the form of " vocabulary switching, " -- using the terminology of one source to search another and identifying the same concept expressed with different words. Scientists need this technology in order to find information outside their specialties effectively. In one of the largest information science calculations to date, ten days of dedicated supercomputer time were used to generate concept spaces for 10 million journal abstracts across one thousand science and engineering subject areas.
An important addition to the Alexandria Digital Library project (one of the six projects under the cross-agency research initiative) is a gazetteer that maps named earth features (such as towns or rivers) to their spatial footprints, a critical attribute of a geographic information system. This mapping was produced by merging the Geographic Names Information System Gazetteer (which characterizes an international set of features and is obtained from the Defense Mapping Agency) and the Board of Geographic Names gazetteers (which characterizes U.S. geographic features). The integration required error correction and rationalization of the different feature classifications in the two gazetteers. This new gazetteer is used to support content-based searches in which a user enters the name of a geographic feature, and the search engine retrieves the footprint of the feature, which is then matched with footprints of items (such as maps and images) in the collection.
Another digital library project provides on-line access to a large collection of California environmental data. An innovative " news-on-demand" service provides search and retrieval of radio and television broadcast news stories tailored to a user defined profile. This service delivers news items to a subscriber on a regular basis via the Internet.
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The Informedia system is a Digital Video Library with voice recognition allowing users to enter semantic queries. The query results are displayed in rank order with a video snippet to provide context. |
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