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Searching and browsing multiple subject gateways in the Renardus Service. Michael Day UKOLN, University of Bath RC33 6th International Conference on Social Science Methodology, Amsterdam, The Netherlands, 16-20 August 2004. http://www.ukoln.ac.uk/. Outline. Subject gateways
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Searching and browsing multiple subject gateways in the Renardus Service Michael DayUKOLN, University of Bath RC33 6th International Conference on Social Science Methodology, Amsterdam, The Netherlands, 16-20 August 2004 http://www.ukoln.ac.uk/ 6th International Conference on Social Science Methodology, Amsterdam, 2004
Outline • Subject gateways • The Renardus Service • Cross-searching • Cross-browsing • Issues • Future potential 6th International Conference on Social Science Methodology, Amsterdam, 2004
What are subject gateways? (1) • Discovery services that give access to high-quality Web resources: • Selective (published criteria) • Typically based on resource description (metadata) • Provides users with search and browse facilities • Use subject classification systems for subject browsing 6th International Conference on Social Science Methodology, Amsterdam, 2004
What are subject gateways? (2) • An example: • Resource Discovery Network (UK) • Includes the Social Science Information Gateway (SOSIG) • Pioneer of the subject gateway concept • Now a mature service (>25K resources) run by the Institute of Learning and Research Technology (ILRT) at the University of Bristol • http://www.sosig.ac.uk/ 6th International Conference on Social Science Methodology, Amsterdam, 2004
RDN Social Science Information Gateway (August 2004) http://www.sosig.ac.uk/ 6th International Conference on Social Science Methodology, Amsterdam, 2004
What is the Renardus Service? • A broker service that integrates access to European subject gateways (all subjects) • Developed by a research project funded 2000-2002 by the European Commission as part of its Information Society Technologies (IST) programme • Since 2002, managed by participating gateways through the Renardus Consortium • Operational service hosted by the Goettingen State and University Library (SUB) • http://www.renardus.org/ 6th International Conference on Social Science Methodology, Amsterdam, 2004
Services participating in Renardus 6th International Conference on Social Science Methodology, Amsterdam, 2004
Cross-searching • Searches across all participating services: • Uses the Z39.50 protocol • Services provide metadata that conforms to the Renardus "application profile": • Based on the Dublin Core Metadata Element Set (DCMES) • Added element: Country (of origin) • Mandatory elements:Identifier, Title, Description, Subject, … 6th International Conference on Social Science Methodology, Amsterdam, 2004
Cross-browsing (1) • Renardus needed to provide subject browse access across all services • Subject gateways use many different subject schemes for browsing • Some 'home-grown' • Others based on (or adapted from) standards (e.g., DDC, LCC, UDC, MSC, Nederlandse Basisclassificatie) • Also some variation in the depth of browsing structure (between 1 and 5 levels), although most are shallow 6th International Conference on Social Science Methodology, Amsterdam, 2004
Cross-browsing (2) • Renardus chose to map local schemes to a universal classification scheme - the Dewey Decimal Classification (DDC): • Available online (WebDewey) • Covers all subjects, is frequently updated, has global use, etc. • The project negotiated a research license from OCLC Forest Press 6th International Conference on Social Science Methodology, Amsterdam, 2004
Classification mapping (1) • General approach: • Mapping to local browse system, not to individual resources • The mapping is one-way only, from the DDC to the local browsing system • Mappings move from top levels of browse structures before moving progressively down it 6th International Conference on Social Science Methodology, Amsterdam, 2004
Classification mapping (2) • Mapping relationships: • Simple equivalence between terms not expected • Five mapping relationships • Fully equivalent • Narrower equivalent • Broader equivalent • Major overlap • Minor overlap 6th International Conference on Social Science Methodology, Amsterdam, 2004
Classification mapping (3) • Syntax: LN (Local classification notation)LC (Local classification caption)RL (Relationship code, i.e. =, >, <, MJ, or MN)DN (DDC notation)DC (DDC caption)UR (Local browsing URL for the class)NT (Notes):RE: (Record end) 6th International Conference on Social Science Methodology, Amsterdam, 2004
Classification mapping (4) • Technical solutions: • Mapping tool developed by the German CARMEN project (CarmenX) • Participating gateways provide a machine-readable version of the classification scheme in use • The tool (together with WebDewey) facilitates the production of the mapping information in the correct syntax 6th International Conference on Social Science Methodology, Amsterdam, 2004
[Renardus Mapping Tool] 6th International Conference on Social Science Methodology, Amsterdam, 2004
Using the mapping information • In Renardus, the DDC mapping information provides: • The basis of the cross-browse feature • Information for the advanced search feature, e.g. search by DDC Classification • The DDC browse structure forms the core part of the Renardus Service Web page [Next slide …] 6th International Conference on Social Science Methodology, Amsterdam, 2004
6th International Conference on Social Science Methodology, Amsterdam, 2004
Cross-browsing in Renardus • Based on a two-step process • first browsing within the DDC structure on the Renardus Web pages • Then linking directly to the browse structures in local gateways • Called "Browse and jump" • Interface issues • Visual inconsistency • No clear path back to Renardus from the local gateways 6th International Conference on Social Science Methodology, Amsterdam, 2004
Navigational support • Need for additional navigational support in large browsing structures • Renardus developed some experimental features: • Searching for a different start page • Graphical navigation overview • Merge 6th International Conference on Social Science Methodology, Amsterdam, 2004
[Graphical Navigation Overview] 6th International Conference on Social Science Methodology, Amsterdam, 2004
Issues • Sustainability • EU-funded project, no significant funding to develop the service further • Technology developments • Renardus cross-search currently based on Z39.50 • New distributed search technologies now available: • SRW Search/Retrieve Web Service • OAI-PMH - already used for cross-searching within the RDN 6th International Conference on Social Science Methodology, Amsterdam, 2004
Future potential (1) • Multilinguality • Because DDC has been translated into many languages, it is possible to add other language versions of the browse system into Renardus • Automatic classification support for the mapping process • Managing the mapping information is a big commitment for participating services • Terminology services • Web services that combine knowledge organisation systems and vocabularies - could replace custom-built mappings in Renardus 6th International Conference on Social Science Methodology, Amsterdam, 2004
Future potential (2) • Web archiving initiatives • Not just describing Web resources, but collecting them for future use (long term preservation) • Two main approaches to collection: • Selective approach • Selection, negotiation of rights, harvesting • Used by some national libraries and archives, also for special collections (e.g. political parties, elections) • Automatic harvesting approach • Robot-based • Used by the Internet Archive, some national libraries, etc. 6th International Conference on Social Science Methodology, Amsterdam, 2004
Future potential (3) • Web-archiving (continued) • The selective approach has some commonality with current subject gateway practice • e.g., The need for selection criteria and descriptive metadata • This may be a possible area for collaboration in the future … and of interest to social scientists 6th International Conference on Social Science Methodology, Amsterdam, 2004
Further information: • Renardus Service: http://www.renardus.org/ • Social Science Information Gateway: http://www.sosig.ac.uk/ • UKOLN:http://www.ukoln.ac.uk/ 6th International Conference on Social Science Methodology, Amsterdam, 2004