420 likes | 652 Views
Metadata Models. XML Metadata Models RDF (Resource Description Framework) FRBR (Functional Requirements for Bibliographic Records) (for information resources) DCAM (Dublin Core Abstract Model) Metadata applications Experiment with other tools
E N D
Metadata Models • XML • Metadata Models • RDF (Resource Description Framework) • FRBR (Functional Requirements for Bibliographic Records) (for information resources) • DCAM (Dublin Core Abstract Model) • Metadata applications • Experiment with other tools • Processes, people, and applications (may extend to next week)
Metadata Models • Modeling/frameworks, packaging • RDF (Resource Description Framework) • FRBR (Functional Requirements for Bibliographic Records) (for information resources) • DCAM (Dublin Core Abstract Model) • METS (Metadata Encoding Transformation Standard) • Z39.50 Many others…. Goal: Interoperability++ (structural*, semantic, syntactic)
RDF (Resource Description Framework) • Outgrowth of PICS (Platform for Internet Content Selection) for and the Warwick framework • PICS-NG (Next Generation) • Warwick, England DC-2 (1996) • Shortcomings, but wide applicability • Bringing together metadata needs of many communities
Warwick Framework PICS V-Card Dublin Core VRA-Core Administrative Core
RDF • An infrastructure for encoding, exchange and reuse of structural metadata • XML for the exchange and processing of text (vendor independent, etc.) • XML allows RDF to impose structure • Unambiguous, consistent expression of semantics
RDF • Ability to define metadata • Semantic modularity!! • Re-use and extend semantics • Vocabulary/metadata/attribute registries (IEC 11179, http://metadata-stds.org/11179) • Distributed registries, although limitations • Means for publishing machine-processable and human-readable metadata • Interoperability • A Model….
RDF Model Author Webpage: http://ils.unc.edu “Abe Crystal” (Value) Object (Resource) Subject (Property type) Predicate • “The author of the SILS Webpage is Abe Crystal” http://ils.unc.edu has a creator with name Abe Crystal • A literal, a triple, a statement
Iterative descriptive process http://ils.unc.eduhas a creator with name Abe Crystal http://ils.unc.edu has a creation date with value October 2004 http://ils.unc.eduhas a language with value English
RDF as a Directed Graph resource http://ils.unc.edu Language properties Creation date Creator English Abe Crystal October 2004
RDF as a Directed Graph resource Abe Crystal email properties name affiliation UNC Crystal, Abe crystal@unc.edu
RDF Syntax There are two important abstractions that lend power to RDF: • Almost anything can be a resource • a web page • a person • a cell phone or PDA • Properties (i.e. relationships) are given semantics • Process can continue down many levels. Practical limits? • No one right answer, depends on the domain requirements
DC in RDF Expressing Simple Dublin Core in RDF/XML (Beckett, et al., 2002) • http://dublincore.org/documents/dcmes-xml/ • *note, remember, you cannot do qualification with this recommendation. Expressing Qualified Dublin Core in RDF / XML (Kokkelink & Schwänzl, 2002) • http://dublincore.org/documents/2002/04/14/dcq-rdf-xml/
DC in RDF (ex.1) (Beckett, et al, 2002) <rdf:Description> <dc:title> Expressing Simple Dublin Core in RDF/XML </dc:title> <dc:creator>Dave Beckett </dc:creator> <dc:creator>Eric Miller</dc:creator> </rdf:Description>
DC in RDF (ex. 2) (Beckett, et al, 2002) <rdf:Description> <dc:title>Internet Ethics</dc:title> <dc:creator>Duncan Langford</dc:creator> <dc:format>Book</dc:format> <dc:identifier>ISBN 0333776267</dc:identifier> </rdf:Description>
RDF(ex. 3-1) <?xml version="1.0"?> <rdf:RDF xmlns:rdf=“http://www.w3.org/TR/2004/REC-rdf-schema-20040210/”xmlns:dc=“http://dublincore.org/documents/dces/"xmlns:vCard=“http://www.imc.org/rfc2425”><rdf:Description about=“http://identifier goes here”>
RDF(ex. 3-2) <dc:creator>Beverly B. Hermalyn</dc:creator> <dc:creator>Marc D. Horowitz.</dc:creator> <vCard:address>13 Morning Lane</vCard:address > <dc:subject>Birth announcement</dc:subject><dc:description>6 lbs., 6oz. ; 20 in. </dc:description> </rdf:Description> </rdf:RDF>
RDF(ex. 4-1) <?xml version="1.0"?> <rdf:RDF xmlns:rdf="http://www.w3.org/TR/2004/REC-rdf-schema-20040210/”xmlns:dc="http://dublincore.org/documents/dces" xmlns:ac="http://purl.org/dc/admincore/2.0/"> <rdf:Description about="http://www.geocities.com/Athens/Acropolis/photo/6681/"> <dc:title>The Acropolis</dc:title>
RDF(ex. 4-2) <dc:creator>Barnette, Paul J. Jr.</dc:creator> <ac:name >Joe Datatranscriber</ac:name > <ac:date>2006-02-14</ac:date> <dc:subject>Acropolis</dc:subject><dc:subject>Greek history</dc:subject> <dc:coverage>Athens, Greece</dc:coverage></rdf:Description> </rdf:RDF>
Type Qualification in RDF (ex. 5-1) • Declared: rdf, dc, dcq, ac, & lcsh namespaces • <rdf:Description rdf:about=http://ils.unc.edu> • <dc:title>….</dc:title> • <dc:creator> • <rdf:Description> • <rdf:value>Abe Crystal</rdf:value> • <dcq:creatorType>PersonalName</dcq:…> • </rdf:Description> • <dc:creator> • * One way that people have worked w/RDF and qualification
Scheme Qualification in RDF (ex. 5-2) <dc:subject> <rdf:Description> <rdf:value>Information science</rdf:value> <dcq:SubjectScheme>lcsh</dcq:…> </rdf:Description> </dc:subject> * One way that people have worked w/RDF and qualification
RDF • An infrastructure/model for encoding, exchange and reuse of metadata Common conventions of: • Structure: XML allows RDF to impose structure • Unambiguous, consistent expression of semantics • Semantics: Element definitions from different resource descriptions/communities • Syntax: XML for the exchange and processing of text (vendor independent, etc.)
<rdf:RDF xmlns:rdf="http://www.w3.org/TR/WD-rdf-syntax#" xmlns:sm="http://www.mozilla.org/smart-mail/schema#"> <rdf:Description about="http://www.mozilla.org/smart-mail/get-mail.cgi?user=waterson&folder=inbox"> <sm:message id="4025293"> <sm:recipient>Chris Waterson “waterson@netscape.com”</sm:recipient> <sm:sender>Aunt Helga "helga@netcenter.net"</sm:sender> <sm:received-by>x-wing.mcom.com</sm:received-by> <sm:subject>Great recipe for Yam Soup!</sm:subject> <sm:body> http://www.mozilla.org/smart-mail/get-body.cgi?id=4025293 </sm:body> </sm:message> <sm:message id="4025294"> … </sm:message> </rdf:Description> </rdf:RDF> Mozilla RDF : Smart Mail Inbox (slide from Eric Obershaw, from 210-92, Fall, 2000)
FRBR • Work/item • C.A. Cutter (1890) • Notion of a work • S. R. Ranganathan (1930-late 1960) • Intellectual entity – expressed thought • Physical entity – embodies thought • P. Wilson • Intellectual entity – work • Subject metadata • Physical entity – item • Selected descriptive metadata
Work, expression, manifestation, item • the work, a distinct intellectual or artistic creation • the expression, the intellectual or artistic realization of a work • the manifestation, the physical embodiment of an expression of a work • the item, a single exemplar of a manifestation
Work, expression, manifestation, item IFLA FRBR (Functional Requirement for a Bibliographic Record) • Work, Expression, Manifestation, Item http://www.ifla.org/VII/s13/frbr/frbr.htm • w1Gone with the Wind (motion picture) • e1 the original English language version • e2 the original with French subtitles added
Work, expression, manifestation, item w1Rolling Stones’ IT'S ONLY ROCK-N –ROLL(1974) • e1 the groups performance recorded for the album • m1 the recording released in 1974 by MCA Records on tape cassette • m2 the recording released in 1974 by MCA Records on compact disc
Work, expression, manifestation, item w1 Jean Jolivet's Vraie description des Gaules.... e1 the cartographer's original rendering • m1 the map issued in 1570 • i1 a copy in the Département des Cartes et plans at the Bibliothèque nationale in Paris • m2 a facsimile reproduction published in 1974 by Hier et demain
FRBR diagram I: UNC Musllib.CD, RCA, 2005 c.3 I: Your CD, RCA, 2005 c.1 M: CD, RCA, 2005 I: My CD, RCA, 2005 c.2 E: Music (just the instruments) E: Music and lyrics Work, the Performance (1974) M: RS, LP 1974 M: 8-track, RCA, 1975
Dublin Core Abstract Model • The DCAM is a conceptual model. • The DCAM is still under development
Dublin Core Abstract Model • Anything can be a resource (a book, a webpage, a person, a metadata element/property, e.g. "title") • To describe a resource, we make statements (e.g., the "title" of the digital resource is "William Shakespeare's life.“) • We also make statements about the value of a resource • the "title" "William Shakespeare and his life" is an "alternative • the "subject" of "English literature" is a library of congress subject
Dublin Core Abstract Model • Metadata record is essentially a "description" that is comprised of one or more statements about a resource - e.g. the "title" of the resource is..., the "subject" of the resource is... and so forth. • Each statement is made up of a "property" and a "value," so, "title“ and "subject" are properties, and they are assignment values Descirption sets = records
Records • Description sets are instantiated, for the purposes of exchange between software applications, in the form of metadata records • Each record conforms to one of the DCMI encoding guidelines (XHTML meta tags, XML, RDF/XML, etc.) <dc:title> a document </dc:title> <dc:creator> andy powell </dc:creator> record
Simple vs. qualified DC? • Within DCMI, we often use the phrases “simple DC” and “qualified DC” • “Simple DC” only supports a single description using the 15 DCMES elements with value strings • “Qualified DC” supports all the features of the abstract model, and allows the use of all DCMI terms as well as other, non-DCMI, terms note that not everyoneagrees with Andy Powell’sdefinitions!
Dumb-down • the process of translating qualified DC into simple DC is normally referred to as ‘dumbing-down’ element value uninformed informed
record (encoded as XHTML, XML or RDF/XML) description set description (about a resource (URI)) vocabulary encoding scheme (URI) statement property (URI) value (URI) representation syntax encodingscheme (URI) value string OR rich value OR related description language(e.g. en-GB) Model summary
An Interoperability Model • Semantic Interoperability • Feature: Definition/meaning, vocabulary • Facilitated by:Metadata registries, Application profiles, and Crosswalks • Structural Interoperability • Feature: Modeling/frameworks, packaging • Facilitated by: RDF, FRBR, Z39.50 (model/protocol), METZ, OAIS, DCAM • Syntactical Interoperability • Feature: Encoding • Facilitated by: X/HTML, XML, MARC, punctuation
Metadata Applications • http://www.asis.org/Bulletin/Dec-02/ASISTDecJan.pdf