6th International Conference on Social Science Methodology, Amsterdam, 2004 Searching and browsing multiple subject gateways in the Renardus Service Michael.

6th International Conference on Social Science Methodology, Amsterdam, 2004

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/


Outline

• Subject gateways

• The Renardus Service– Cross-searching– Cross-browsing

• Issues

• Future potential


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


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/


RDN Social ScienceInformation Gateway(August 2004)

http://www.sosig.ac.uk/


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/


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


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, …


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


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


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



• Mapping relationships:– Simple equivalence between terms not

expected– Five mapping relationships

• Fully equivalent• Narrower equivalent• Broader equivalent• Major overlap• Minor overlap



• 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)



• 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]


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 …]



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


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


[Graphical Navigation Overview]


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


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



• 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.



• 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


Further information:

• Renardus Service: http://www.renardus.org/

• Social Science Information Gateway: http://www.sosig.ac.uk/

• UKOLN:http://www.ukoln.ac.uk/

Thank-you for your attention!

Examples

1. Simple and advanced searching


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)




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 …]

6th International Conference on Social Science Methodology, Amsterdam, 2004[Record from participating gateway (DutchESS)]

6th International Conference on Social Science Methodology, Amsterdam, 2004[Record from participating gateway (RDN Biome)]


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



Advanced searching (2)

• Other options:– Limit (filter) search by Document Type,

Language, or Country– Display options and search timeout– Select which gateways to search


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 …]

Examples

2. Cross-browsing






– 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 …]




– 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 …


6th International Conference on Social Science Methodology, Amsterdam, 2004[Finnish Virtual Library]

6th International Conference on Social Science Methodology, Amsterdam, 2004[DDB]

Additional information on navigation support features in Renardus cross-

browsing


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



– 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 …]






– 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 …]




• Merge– A short cut to viewing individual resource

descriptions from all related collections– Similar to "DDC Classification" search in

advanced search feature




6th International Conference on Social Science Methodology, Amsterdam, 2004 Searching and browsing multiple subject gateways in the Renardus Service Michael.

Documents

social science methodology

th international conference

subject browsing slide

services subject gateways

european subject gateways

classification mapping

subject classification

multiple subject gateways