1. Cross-browsing subject gateways with the Dewey Decimal Classification in the Renardus Service Michael Day UKOLN, University of Bath m.day@ukoln.ac.uk JISC Terminology Services Workshop, London, 13 February 2004

2. JISC Terminology Services Workshop, London, 13 February 2004 What is the Renardus service? –A broker service that integrates access to European subject gateways –Developed by a research project funded 2000-2002 by the European Commission as part of the Information Society Technologies (IST) programme –Managed by participating gateways through the Renardus Consortium –Operational service hosted by Goettingen State and University Library (SUB)

3. JISC Terminology Services Workshop, London, 13 February 2004 What are subject gateways? Discovery services that give access to high-quality Web resources: –Selective (defined criteria) –Based on resource description (metadata) –Search and browse facilities –Use subject classification for subject browsing –Many examples: RDN (UK), EdNA Online (Australia), etc.

4. JISC Terminology Services Workshop, London, 13 February 2004 Participating gateways DAINet - German Agricultural Information NetworkDE Denmark's Electronic Research Library (DEF)DK DutchESS - Dutch Electronic Subject ServiceNL Finnish Virtual Library (FVL), NOVAGateFI Online dissertations (Die Deutsche Bibliothek)DE Resource Discovery Network (RDN)UK SSGFI gateways at SUB Goettingen (Anglistik Guide, Geo-Guide, History Guide, MathGuide) DE

5. JISC Terminology Services Workshop, London, 13 February 2004 Cross-searching Uses the Z39.50 protocol Renardus application profile: –Based on the Dublin Core Metadata Element Set (DCMES) –Added element: –Country –Mandatory elements: –Identifier, Title, Description, Subject …

6. JISC Terminology Services Workshop, London, 13 February 2004 Search example Simple search for "palaeontology" –Renardus searches each participating gateway using the Z39.50 protocol –Retrieves hits from multiple gateways: RDN (129) Geo-Guide (123) NOVAGate (2) DutchESS (1) FVL (1) –Displays results (detailed or brief)

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9. JISC Terminology Services Workshop, London, 13 February 2004 Linking to resources –The results display the URL of the described resource as a hyperlink –Users can also refer to the richer metadata record provided by the participating gateway –The level of detail varies … –Examples from DutchESS and RDN (Biome) follow … [Next two slides …]

10. JISC Terminology Services Workshop, London, 13 February 2004 [Record from participating gateway (DutchESS)]

11. JISC Terminology Services Workshop, London, 13 February 2004 [Record from participating gateway (RDN Biome)]

12. JISC Terminology Services Workshop, London, 13 February 2004 Advanced searching (1) Search options –Simple Boolean AND/OR searching on the content of individual elements Title, Subject, Description, Creator, DDC Classification, Document Type –Term selection help For the elements: Title, DDC Classification, Subject and Type, a "term selection window" opens in some browsers to indicate terms that are already included in gateway indexes

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14. JISC Terminology Services Workshop, London, 13 February 2004 Advanced searching (2) Other options: –Limit (filter) search by Document Type, Language, or Country –Display options and search timeout –Select which gateways to search

15. JISC Terminology Services Workshop, London, 13 February 2004 Cross-browsing (1) Enhanced subject access a key part of the services offered by subject gateways Subject gateways, however, use many different subject schemes –Some 'home-grown' –Others based on (or adapted from) standards

16. JISC Terminology Services Workshop, London, 13 February 2004 Cross-browsing (2) Subject schemes in use within Renardus: –Nederlandse Basisclassificatie - DutchESS –AGRIS main subject categories - NOVAGate –Göttinger Online-Klassifikation (GOK) - Geo- Guide, Anglistik Guide, History Guide –DDC - parts of RDN –Universal Decimal Classification (UDC) - parts of RDN –Mathematics Subject Classification (MSC) - MathGuide –etc.

17. JISC Terminology Services Workshop, London, 13 February 2004 Cross-browsing (3) Also much variation in the depth of browsing structure (between 1 and 5 levels), although most are shallow Given this variety, how could browsing across the content of gateways be done in the broker service? Answer = mapping local schemes to a universal classification scheme

18. JISC Terminology Services Workshop, London, 13 February 2004 Cross-browsing (4) For this, the Renardus project chose the Dewey Decimal Classification (DDC): –Available online (WebDewey) –Covers all subjects, is frequently updated, has global use, etc. –Negotiated a research license from OCLC Forest Press

19. JISC Terminology Services Workshop, London, 13 February 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

20. JISC Terminology Services Workshop, London, 13 February 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

21. JISC Terminology Services Workshop, London, 13 February 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)

22. JISC Terminology Services Workshop, London, 13 February 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 (with WebDewey) facilitates the production of the mapping information in the correct syntax

23. JISC Terminology Services Workshop, London, 13 February 2004 [Renardus Mapping Tool]

24. JISC Terminology Services Workshop, London, 13 February 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 …]

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26. JISC Terminology Services Workshop, London, 13 February 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

27. JISC Terminology Services Workshop, London, 13 February 2004 Browsing example (1) Browsing for information on 'mineralogy': –Select "science" in first browse level Note broader equivalent mapping to "Technology and Natural Sciences" (DEF) –Then select "chemistry" … Again, note narrower and broader equivalents … [Next three slides …]

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31. JISC Terminology Services Workshop, London, 13 February 2004 Browsing example (2) –Then select "mineralogy" Fully equivalent to "Mineralogy: General" in GOK (Geo-Guide), "Mineralogy" in FVL A narrower equivalent is "Mineral paragenesis" in GOK (Geo-Guide) Major overlap with "Mineralogie, Boden-, Gesteins- und Lagerstättenkunde" in DDB online dissertations [Next slide …]

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33. JISC Terminology Services Workshop, London, 13 February 2004 Browsing example (3) –Selecting the link takes the user to the relevant part of the browse hierarchy in the local gateway –This is known as "browse and jump" –Examples of the relevant local browse hierarchies in FVL and DDB online dissertations follow … [Next two slides …]

34. JISC Terminology Services Workshop, London, 13 February 2004 [Finnish Virtual Library]

35. JISC Terminology Services Workshop, London, 13 February 2004 [DDB]

36. JISC Terminology Services Workshop, London, 13 February 2004 Navigational support (1) Need for additional navigational support in large browsing structures Renardus developed some experimental features: –Searching for an start page –Graphical navigation overview –Merge

37. JISC Terminology Services Workshop, London, 13 February 2004 Navigational support (2) –Finding a different start-page It is possible to find a different page in the browse structure, by entering a term in the search box available on each browsing page This takes you to a results page that links to the HTML and graphical overview versions of the Renardus browse hierarchy [Next three slides …]

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41. JISC Terminology Services Workshop, London, 13 February 2004 Navigational support (3) –Graphical Navigation Overview Gives a 'fisheye' view of the DDC browse hierarchy Allows users to see the browse term (highlighted in red) together with related terms in surrounding classes Terms with content (highlighted in blue) link to the relevant page in the Renardus browse hierarchy [Next slide …]

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43. JISC Terminology Services Workshop, London, 13 February 2004 Navigational support (3) Merge –A short cut to viewing individual resource descriptions from all related collections –Similar to "DDC Classification" search in advanced search feature [Next two slides …]

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45. JISC Terminology Services Workshop, London, 13 February 2004

46. JISC Terminology Services Workshop, London, 13 February 2004 Issues Usability of broker: –Interface consistency –Navigation in large structures Maintenance issues: –Maintenance of mappings (subject gateways are always changing) –Maintenance of links to browse hierarchy in each gateway (e.g., when gateways restructure)

47. JISC Terminology Services Workshop, London, 13 February 2004 Future developments Multilinguality –Because DDC has been translated into many languages, it is possible to add other language versions of the browse system into Renardus –Successfully implemented in the Renardus testbed Automatic classification –Support for mapping process

48. JISC Terminology Services Workshop, London, 13 February 2004 More information on Renardus: –Renardus Service: http://www.renardus.org/ –Traugott Koch, Heike Neuroth & Michael Day, "Renardus: cross-browsing European subject gateways via a common classification system (DDC)," Subject retrieval in an networked world, OCLC, Dublin, Ohio, August 2001: http://www.lub.lu.se/~traugott/drafts/ preifla-final.html