Post on 09-Jan-2016
description
INLS 150 Session 5
February 7, 2002
Cristina PattuelliSchool 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
http://www.ifla.org/VII/s13/frbr/frbr.htm
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
IFLA FRBR
Deconstructing the Library Catalogue, Tom Delsey, National Library of Canadahttp://www.bl.uk/information/news/2709frbr.ppt
Manifestation
Expression
Work
Item
realized through
embodied in
exemplified by
IFLA FRBR
Deconstructing the Library Catalogue, Tom Delsey, National Library of Canadahttp://www.bl.uk/information/news/2709frbr.ppt
Manifestation
Expression
Work
Item
creates
realizes
produces
owns
Corporate body
Person
A typical set of topics/events/relationships
Work
Expression
Manifestation
embodied in...
realised through...
“I conceived it”CREATIONevent
“I did it”REALISATIONevent
“I produced it”EMBODIMENTevent
Poul Henrik Jørgensen, Danish Bibliographic Centre, www.dbc.dk
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 FrameworkDevelopers
Robert KahnCorporation 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 FrameworkMotivation
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 FrameworkKey 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
http://www.cs.cornell.edu/cdlrg/fedora.html
Warwick Framework
April 1996 - OCLC/UKOLN Warwick MetadataWorkshop
(2nd 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!
Description CMS record
Terms & Conditions
Based on a slide by Stu Weibel
Warwick Framework
• No constrains on means of communications– By email, 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 2001
http:/my.domain/doc/author
Pete
• A resource has some property whose value is either (i) a simple string value (literal)….
• The resource identified by the URI http://my.domain/doc/ has a property “author” whose value is “Pete”
• Or, “Pete” is the “author” of the resource identified by http://my.domain/doc/
The RDF Model (2)
• … or (ii) another resource
http://my.domain/doc/author
Pete pete@my.domain
name email
• The value of property “author” is another resource which has a property “name” with value “Pete” and a property “email” with value “pete@my.domain”
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:RDF xmlns:uc=“http://www.ukoln.ac.uk/core/”> <rdf:Description about=”http://my.domain/doc/”> <uc:author>Pete</uc:author> </rdf:Description></rdf:RDF>
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
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 1965. From: http://www.cs.sfu.ca/CourseCentral/365/li/material/notes/Chap1/Chap1.html#HyperMulti
HyperText
http://www.cs.sfu.ca/CourseCentral/365/li/material/notes/Chap1/Chap1.html#HyperMulti
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”