Searching%20and%20browsing%20multiple%20subject%20gateways%20in%20the%20Renardus%20Service

1
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/
2
Outline

• Subject gateways
• The Renardus Service
• Cross-searching
• Cross-browsing
• Issues
• Future potential

3
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

4
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 (gt25K resources) run by the
  Institute of Learning and Research Technology
  (ILRT) at the University of Bristol
• http//www.sosig.ac.uk/

5
RDN Social Science Information Gateway (August
2004) http//www.sosig.ac.uk/
6
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/

7
Services participating in Renardus
DAINet - German Agricultural Information Network DE
Denmark's Electronic Research Library (DEF) DK
DutchESS - Dutch Electronic Subject Service NL
Finnish Virtual Library (FVL), NOVAGate FI
Online dissertations (Die Deutsche Bibliothek) DE
Resource Discovery Network (RDN) UK
SSGFI gateways at SUB Goettingen (Anglistik Guide, Geo-Guide, History Guide, MathGuide) DE
8
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 elementsIdentifier, Title,
  Description, Subject,

9
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

10
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

11
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

12
Classification mapping (2)

• Mapping relationships
• Simple equivalence between terms not expected
• Five mapping relationships
• Fully equivalent
• Narrower equivalent
• Broader equivalent
• Major overlap
• Minor overlap

13
Classification mapping (3)

• Syntax
• LN (Local classification notation)LC (Local
  classification caption)RL (Relationship code,
  i.e. , gt, lt, MJ, or MN)DN (DDC notation)DC
  (DDC caption)UR (Local browsing URL for the
  class)NT (Notes)RE (Record end)

14
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

15
Renardus Mapping Tool
16
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

17
(No Transcript)
18
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

19
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

20
Graphical Navigation Overview
21
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

22
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

23
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.

24
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

25
Further information

• Renardus Service http//www.renardus.org/
• Social Science Information Gateway
  http//www.sosig.ac.uk/
• UKOLNhttp//www.ukoln.ac.uk/

26
Thank-you for your attention!
27
Examples

• 1. Simple and advanced searching

28
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)

29
(No Transcript)
30
(No Transcript)
31
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

32
Record from participating gateway (DutchESS)
33
Record from participating gateway (RDN Biome)
34
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

35
(No Transcript)
36
Advanced searching (2)

• Other options
• Limit (filter) search by Document Type, Language,
  or Country
• Display options and search timeout
• Select which gateways to search

37
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

38
Examples

• 2. Cross-browsing

39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
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

43
(No Transcript)
44
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

45
Finnish Virtual Library
46
DDB
47
Additional information on navigation support
features in Renardus cross-browsing
48
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

49
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

50
(No Transcript)
51
(No Transcript)
52
(No Transcript)
53
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

54
(No Transcript)
55
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

56
(No Transcript)
57
(No Transcript)