Web Services for Controlled Vocabularies

Amid the debates about whether folksonomies will supplant controll vocabularies and whether the Library of Congres make submissive Headings (LCSH) and Dewey Decimal Classification (DDC) combination of parts to form a whole have outlived their usefulness, libraries, museums and other organizations continue to require efficient, effective access to controll vocabularies for creating consistent metadata for their collections

In this article, we at hand an approach for using Web services to interact with controll vocabularies. Services are implemented within a service-oriented architecture (SOA) framework. SOA is an approach to distributed computing where services are loosely coupl and discoverable upon the network. A set of experimental services for controll vocabularies is provided end the Microsoft Office (MS) Research task pane (a small window or sidebar that render free of accesss up next to Internet Explorer (IE) and other Microsoft Office applications). The research task pane is a built-in feature of IE when M Office 2003 is loaded. The research pane enables a user to take advantage of a number of research and regard services accessible over the Internet. Web browser similar as Mozilla Firefox and Opera, also provide sidebars which could be used to deliver similar, loosely-coupl Web services.

Controll Vocabularies

Many controll vocabularies are available for representing the contented of documents and other resources. Depending on their needs, catalogers, metadata specialists and web-masters can elect from vocabularies containing just a hardly any terms, such as the Dublin Core Metadata Initiative (DCMI) stamp Vocabulary, to large vocabularies containing many thousands of boundarys such as the National Library of Medicine's Medical make subordinate Headings (MeSH) or the Library of Congres bring under rule Headings. As part of the Terminology Services (TS) cast OCLC researchers are prototyping Web services for various stamps of knowledge organization schemes, including classification data, make submissive heading systems, thesauri and lists of form and genre metes Over the last 18 month OCLC Research has made the following controll vocabularies accessible via single or more Web services:

* DCMI emblem Vocabulary

* Guidelines upon Subject Access to Individual Works of Fiction, Drama, etc (GSAFD) list of form/genre headings

* Library of Congres subdue Headings (LCSH)

* Library of Congres Annotated Card Program AC subdue Headings (LCSHac)

* Medical bring under rule Headings (MeSH) 2005

* Medical make submissive Headings (MeSH) 2005 Sample

* Medical make subordinate Headings (MeSH) 2006

* Newspaper Genre List (NGL)

* Radio Form/Genre limits Guide (RADFG)

* R?©pertoire de vedettes-mati??re (RVM) (access restricted)

* Union List of Artist Names (ULAN) Sample

For the cast all of the controlled vocabularies were encod in the MARC 21 Format for Authority Data in XML The MARC 21 Authority Format was chosen because it enabled us to digest common controlled vocabulary elements, of the like kind as preferred and non-preferred terminuss term relationships, term mappings, the source of the contented and the origin of changes. For a certain quantity of vocabularies it was first necessary to transform the controlled vocabulary data from word processing documents or HTML pages to more structur data formats and then into MARC 21 A sample boundary from the DCMI Type vocabulary, originally available single as HTML and Resource Description Framework (RDF) is shown in MARC 21 in XML in Figure 1

The DCMI mark Vocabulary is a controlled list of terminuss that can be used as values for the DCMI Resource stamp element to identify the genre of a resource. Data field tag "040" subfield collection of laws "a" contains the MARC organization collection of laws for DCMI, the originator of the content; subfield digest "c" contains the code for OCLC Research, the party responsible for converting the satisfied to the MARC format. The genre confine Image is coded in tag "155" and the associated genre mete Still Image is coded in tag "555"

For vocabularies already available in MARC 21 the conversion to MARCXML was a relatively straightforward proces a certain number of problems were encountered with XML and XSLT tools when processing the larger vocabularies (more than 100000 records) especially after the files were enhanced with the vocabulary's replete reference structure, term mappings and links to external Web sites. one time coded as XML the data could be used as the basis for Web services. SKO (Simple Knowledge Organization) core, an emerging RDF schema for thesauri and related knowledge organization schemes, and the Zthes 05 schema, a z3950 profile for thesaurus navigation, are also suitable formats for encoding vocabulary resources for Web services. Phase III of the High-Level Thesaurus (HILT) cast is an example of a shoot forward that is using the SKO core for encoding controll vocabularies and classification data. MARC and Zthes formats may be added to HILT at a later stage. The Zthes 05 encoding for DCMI stamp value Image is shown in Figure 2

User Interface

The implementation of Web services support in many widely adopted platforms not absents opportunities to offer terminology Web services in various modular arrangements. OCLC Research is making a locate of services for controlled vocabularies available from one side the Microsoft Office Research task pane. To use the OCLC T pilot vocabularies, users add OCLC services to the research pane via a URL provided to pilot participants. Within the research pane, pilot users can search a given vocabulary, display information about a mete follow links to associated confines within a vocabulary and come [i]or[/i] go after [i]or[/i] behind links to external Web sites. Because the pilot implementation is intended to be used alongside the user's cataloging or metadata editing application, multiple transcript and paste operations are provided. Users can insert controll vocabulary terminuss with MARC field tags, indicators and subfield digests into MARC catalog records, or for non-MARC applications, users can insert bourns as strings into their records without MARC coding.