Title: Searching and browsing multiple subject gateways in the Renardus Service
1Searching 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/
2Outline
- Subject gateways
- The Renardus Service
- Cross-searching
- Cross-browsing
- Issues
- Future potential
3What 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
4What 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/
5RDN Social Science Information Gateway (August
2004) http//www.sosig.ac.uk/
6What 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/
7Services 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
8Cross-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,
9Cross-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
10Cross-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
11Classification 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
12Classification mapping (2)
- Mapping relationships
- Simple equivalence between terms not expected
- Five mapping relationships
- Fully equivalent
- Narrower equivalent
- Broader equivalent
- Major overlap
- Minor overlap
13Classification 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)
14Classification 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
15Renardus Mapping Tool
16Using 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)
18Cross-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
19Navigational 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
20Graphical Navigation Overview
21Issues
- 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
22Future 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
23Future 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.
24Future 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
25Further information
- Renardus Service http//www.renardus.org/
- Social Science Information Gateway
http//www.sosig.ac.uk/ - UKOLNhttp//www.ukoln.ac.uk/
26Thank-you for your attention!