INLS 150 Session 5 February 7, 2002 Cristina Pattuelli School of Information & Library Science UNC

Information Architecture An open architectural framework provides information access and aggregation or integration across diverse domains, including different communities, different types of information and different technologies.

FRBR 1998 IFLA, Functional Requirements for Bibliographic Records

Objectives of a Bibliographic System To find a document/entity that corresponds to user’s search criteria To identify an entity To select an entity that is appropriate to the user’s needs To acquire/obtain access to the entity described The Intellectual Foundation of Information Organization, Elaine Svenonius, 2000

Poul Henrik Jørgensen, Danish Bibliographic Centre,

Information Frameworks Kahn/Wilensky framework (K/W) Warwick Framework (WF) –Offer a conceptual foundation for an open architectural framework FEDORA begins to implement key concepts from K/W and WF IFLA FRBR W3C RDF

Khan/Wilensky Framework Developers  Robert Kahn Corporation for National Research Initiatives (CNRI)  Robert Wilensky University of California at Berkeley  Their research was supported by the Advanced Research Project Agency - May 1995

Kahn/Wilensky Framework Motivation To develop an infrastructure with open architecture for supporting a large and extensible class of distributed digital information services

Kahn/Wilensky Framework Architecture The System Digital Objects Handle, Handle generators Metadata, Key metadata Repositories - RAP Originators Users Global/Local naming authorities

Kahn/Wilensky Framework Key Components Digital Object = data + key-metadata Metadata includes the Handle = unique identifier of the Digital Object RAP (Repository Access Protocol)

FEDORA Flexible and Extensible Digital Object and Repository Architecture (FEDORA) Developed by Digital Library Research Group at Cornell University - A DARPA funded project

Warwick Framework April OCLC/UKOLN Warwick MetadataWorkshop (2 nd Dublin Core Metadata Workshop)

Warwick Framework 1.Need of architecture for the interchange of a wide variety of separately maintained metadata models 2. Need to insure extensibility of schemas

Warwick Framework Consensus was reached on: A high-level infrastructure for aggregating and interchanging multiple metadata packages associated with a common resource WF as the first practical approach to the effective integration of metadata into a global information infrastructure

Warwick Framework Architecture Containers Packages

Warwick Framework Architecture Container = unit for aggregating metadata packages –Transient –Persistent

Warwick Framework Architecture Packages types: –Metadata set –Indirect –Container itself

Warwick Framework Architecture  Container-package architecture Users or software agents able to aggregate discrete packages in a conceptual container No assumption about the content of the packages Containers and packages have identifiers for cross-reference on another

Warwick Framework Container

Warwick Framework Architecture Advantages:  Consistency in aggregating and exchanging metadata  Extensibility via modularity (LEGO metaphor) - vs. redundancy and overlapping - additional elements to support local or discipline-specific requirements

Extending DC (modularity) Modular extensibility… Additional elements to support local needs Complementary packages of metadata …but only if we get the building blocks right! DescriptionCMS record Terms & Conditions Based on a slide by Stu Weibel

Warwick Framework No constrains on means of communications –By , file transfer, HTTP, etc. Implemented using MIME or SGML

RDF RDF is the core technology of the W3C’ Metadata Activity Provides a coherent umbrella framework suitable for use by the various metadata applications of W3C Has been highly influenced by Warwick Framework RDF embraces and extends the philosophy of WF to allow what has been called “fine grained’ metadata mixing

RDF –Resource Description Framework Model & Syntax –Recommendation of W3C, 1999 –Generic “architecture” for metadata set of conventions for applications exchanging metadata allow semantics to be defined by different resource description communities accommodate mixing of metadata from diverse sources XML and Educational Metadata, SBU, London, 10 July 2001

RDF –Defines model for making statements about resources conventions for encoding statements using XML syntax –Object types Resource : any object identified by URI –not necessarily accessible via Web Property : attribute to describe resource –properties also uniquely identified by URI Statement : triple of specific resource, named property, and value XML and Educational Metadata, SBU, London, 10 July 2001

The RDF Model XML and Educational Metadata, SBU, London, 10 July author Pete A resource has some property whose value is either (i) a simple string value (literal)…. The resource identified by the URI has a property “author” whose value is “Pete” Or, “Pete” is the “author” of the resource identified by

The RDF Model (2) … or (ii) another resource author name The value of property “author” is another resource which has a property “name” with value “Pete” and a property “ ” with value XML and Educational Metadata, SBU, London, 10 July 2001

The RDF XML Syntax – –XML representation of model store/exchange descriptions – –Property names made unique through use of XML namespaces. – –Variant syntaxes <rdf:Description about=” Pete XML and Educational Metadata, SBU, London, 10 July 2001

RDF Schema – –Resource Description Framework Schema – –Candidate Recommendation of W3C, 2000 – –Provides mechanisms to define vocabularies used in RDF statements e.g. Dublin Core metadata element set defined using RDF(S) XML and Educational Metadata, SBU, London, 10 July 2001

RDF Schema – –Defines type system resources grouped into classes classes related hierarchically (subClassOf) properties related hierarchically (subPropertyOf) use of properties constrained (domain, range) – –RDF Schema employs RDF model expressible using RDF/XML syntax

RDF, XML & Interoperability – –Why isn’t XML enough? simple statement could be expressed in XML in many different ways human reader makes interpretation/guess application program requires prior knowledge of schema/DTD design RDF imposes extra syntactic constraints on how statement expressed with RDF/XML, both human and program can interpret description consistently – –Less flexibility, greater interoperability XML and Educational Metadata, SBU, London, 10 July 2001

RDF, XML & Interoperability – –Use XML for exchange when applications both “know” semantics conveyed by structure of (meta)data – –Use RDF/XML for exchange when (meta)data potentially used by applications without prior “knowledge” of specific schema (meta)data incorporates overlapping structures from different domains XML and Educational Metadata, SBU, London, 10 July 2001

Memex = Memory Extension Vannevar Bush “A device where an individual stores all his books, records, and communications, and which is mechanized so that it may be consulted with exceeding speed and flexibility”

HyperText Hypertext is a text which contains links to other texts. The term was invented by Ted Nelson around From:

HyperText

Xanadu / Ted Nelson “Xanadu is the original hypertext and interactive multimedia system, under continuous development since 1960” “Docuverse”

The Road to Xanadu In Xanadu did Kubla Khan a stately pleasure-dome decree... Samuel Taylor Coleridge, "Kubla Khan”