inls 150 session 5 february 7, 2002

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


• Container = unit for aggregating metadata packages– Transient– Persistent


• Packages types:– Metadata set

– Indirect

– Container itself


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


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


The RDF Model


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 [email protected]

name email

• The value of property “author” is another resource which has a property “name” with value “Pete” and a property “email” with value “[email protected]”


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>


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)



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


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


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”

inls 150 session 5 february 7, 2002

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