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Published byFelix Bates Modified over 8 years ago
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The Web-DL Environment for Building Digital Libraries from the Web P. Calado 1, M. Gonçalves 2, E. Fox 2, B. Ribeiro-Neto 1, A. Laender 1, A. da Silva 3, D. Reis 1, P. Roberto 1, M. Vieira 1, J. Lage 1 1 Federal University of Minas Gerais 2 Virginia Tech 3 Federal University of Amazonas Project I3DL: Integrating Network Representations and Inference Models to Generate Tailored and Interoperable Digital Libraries from Specifications
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Introduction The Web Largely unstructured No assumptions about users Huge volume of information Digital Libraries Information is explicitly organized, described, and managed Users have broad interests but are more specialized Controlled environment
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Moving From the Web to a Digital Library Structure of data Knowledge of users/tasks LowHigh Digital Libraries Web Databases
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The Web-DL Environment Combines data extraction and DL tools to: Collect data from the Web Normalize the data Make the data publicly available Thus providing: Services and organization of a DL Access to the breadth of Web contents
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Context Federated digital library systems Autonomous and heterogeneous Different systems/protocols Challenges: interoperability, data fusion, etc. Networked Library of Theses and Dissertations (NDLTD) 176 members (and growing) Continuous flow of new data (ETDs) Not all support the same protocols/standards
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Related Work The Harvest system Physnet Greenstone The New Zealand Digital Library
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Web-DL Architecture From the Web to a DL in 3 steps: 1. Crawl Web sites to collect pages 2. Parse the pages to extract the data, mapping it to a standard format 3. Make the data available through a standard protocol (to a DL service provider)
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Web-DL Architecture
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Collecting Web pages: the ASByE tool Generates agents for collecting Web pages Provides a visual metaphor for navigation examples Able to collect both static and dynamic pages
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Extracting the data: the DEByE tool Provides a visual paradigm to specify data examples Generates wrappers based on context Implemented as a Web service
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Normalizing Web data Web data is far from standardized Missing mandatory information Information only implicitly present Data in wrong format Data in wrong encoding A solution: data conversion modules
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Providing DL services: the MARIAN system Configurable from specifications Semantic networks allow a unified representation of complex digital objects and relationships Extensible API
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An example Web DL ETDs were collected from NDLTD member sites 21 different institutions 9595 ETDs Work required: 2—3 examples/field, 9 min./site Major problems found: Sites offline The hidden Web problem Data normalization
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An example Web DL
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Conclusions Moving from the Web to DL is not trivial Site availability, hidden Web Data extraction Data normalization A general solution depends on solutions for these tasks and on integrating these solutions Web-DL provides and environment for such integration
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Future Work Data integration Data quality estimation Automatic example generation
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