LC and the W3C:LC and the W3C:HistoryHistory

Attended two W3C WorkshopsAttended two W3C Workshops• Indexing/Distributed Search - 1996Indexing/Distributed Search - 1996• Query Language - 1998Query Language - 1998

Joined W3C April 1999Joined W3C April 1999 Attended 2 AC Meetings - Attended 2 AC Meetings -

• November 1999November 1999• May 2000May 2000

Why should libraries care?Why should libraries care?

Libraries have a big stake in several activity areas.Libraries have a big stake in several activity areas. Libraries have significant expertise to offer in several Libraries have significant expertise to offer in several

areas e.g.:areas e.g.:• metadatametadata• identifiersidentifiers• character setscharacter sets• information retrievalinformation retrieval

LC’s interest in W3CLC’s interest in W3C

HTMLHTML StylesheetsStylesheets XMLXML MetadataMetadata graphicsgraphics Character SetsCharacter Sets

IdentifiersIdentifiers Information Information

Retrieval/QueryRetrieval/Query AccessibilityAccessibility Digital Digital

SignaturesSignatures IPRIPR

LC’s interest in W3C - LC’s interest in W3C - CategoriesCategories

As a content As a content providerprovider

Copyright OfficeCopyright Office Nat. Library for Nat. Library for

Blind and Blind and Physically Physically HandicappedHandicapped

Library/part of Library/part of library communitylibrary community

LC’s interest in W3CLC’s interest in W3C

As a content providerAs a content provider• HTMLHTML• StylesheetsStylesheets• XMLXML• graphicsgraphics

Copyright OfficeCopyright Office• Digital SignaturesDigital Signatures• IPRIPR

NLSBPHNLSBPH• AccessibilityAccessibility

Library-related interestsLibrary-related interests

MetadataMetadata Character SetsCharacter Sets IdentifiersIdentifiers Information Retrieval/QueryInformation Retrieval/Query AccessibilityAccessibility

Proposal for URI ActivityProposal for URI Activity

Proposed at November 1999 AC Proposed at November 1999 AC MeetingMeeting• Dan LaLiberte, ChairDan LaLiberte, Chair

Proposal seemed well-received Proposal seemed well-received (certainly, by LC)(certainly, by LC)

Proposal withdrawn abruptly, by Proposal withdrawn abruptly, by Tim Berners-Lee, January 2000Tim Berners-Lee, January 2000

LC was not pleased.LC was not pleased.

URIs (background)URIs (background)

URI: “uniform resource identifier” Originally, Originally, a generalization of:

•URL (uniform resource locator),

• URN (uniform resource name),• URC (uniform resource citation),• and potentially others,

but mainly, URL and URN

The difference (in theory) between URL and URN:

a URL is bound to a location• when resource moves, url changes

a URN is a name• thus location independent, and, in theory,

persistent (whatever “persistent” means)

The Other ViewThe Other View

Distinction between URL and URN is artificial

Both terms should be abolished and replaced by “URI”

thus all identifier “schemes” would be URI schemes (even “http”) and no prefix would be necessary (URL, URN, or even URI).

Reasoning Reasoning

Original URI philosophy: • URLs were a short-term solution and URNs

long-term .• URL would be a temporary identification

mechanism until a location-independent, persistent identifier was developed, the URN.

Now it seems:• URNs won’t be any more persistent

than URLs – persistence is a social problem, not a technical problem

Two Views:Two Views:

URLURL• http:http:• ftp:ftp:• z39.50z39.50• …………....

URNURN• nbn:nbn:• hdl:hdl:

URC?URC?

Http:Http: ftp:ftp: hdl: hdl: tv:tv: urn:urn:

• nbn:nbn:• hdl:hdl:

The ProblemThe Problem

LC frustrated with the pace of LC frustrated with the pace of development and lack of development and lack of progressprogress

no coherent URI infrastructure no coherent URI infrastructure no resolution frameworkno resolution framework

URI IssuesURI Issues

resolution resolution registrationregistration proliferationproliferation persistencepersistence

Degree of centralizationDegree of centralization

referral/re-directionreferral/re-direction

support for human support for human readable -and legacy- readable -and legacy- identifiersidentifiers

separation of metadata separation of metadata from identifierfrom identifier

Unicode supportUnicode support

Primary URI IssuesPrimary URI Issues

RegistrationRegistration• ““what URI is used for ISBN?”what URI is used for ISBN?”

resolution resolution • ““how would it be resolved?”how would it be resolved?”

proliferationproliferation• URI-scheme evolution must be sufficiently URI-scheme evolution must be sufficiently

manageable that browsers can implement a core set manageable that browsers can implement a core set of schemes so users won't be constantly of schemes so users won't be constantly downloading plug-ins for different schemesdownloading plug-ins for different schemes..

persistencepersistence

““Persistence”Persistence”it means different things to different it means different things to different

peoplepeople

Location-independenceLocation-independence• when the resource moves, the identifier remains the samewhen the resource moves, the identifier remains the same

uniquenessuniqueness• only one identifier for a given resourceonly one identifier for a given resource

permanencepermanence• once assigned to a resource, the resource will exist once assigned to a resource, the resource will exist

foreverforever unambiguous - nessunambiguous - ness

• once assigned to a resource, that identifier may never be once assigned to a resource, that identifier may never be assigned to another resourceassigned to another resource

LC’s ViewLC’s View

PPersistence is not a technical problem - it’s a ersistence is not a technical problem - it’s a social problem, and a problem that neither the IETF social problem, and a problem that neither the IETF nor the W3C is equipped to solve.nor the W3C is equipped to solve.

Responsibility for ensuring that URIs( continue to) Responsibility for ensuring that URIs( continue to) resolve to the appropriate content should lie with resolve to the appropriate content should lie with the entity managing that content.the entity managing that content.

Different naming schemes will be used with Different naming schemes will be used with different semantics and administrative policies. different semantics and administrative policies. Resolvers for a naming scheme will be Resolvers for a naming scheme will be responsibility of the body administering the responsibility of the body administering the scheme. scheme.

What’s Missing?What’s Missing?

A framework permitting an evolution of URI A framework permitting an evolution of URI schemes sufficiently manageable that schemes sufficiently manageable that browsers can implement a core set of schemes browsers can implement a core set of schemes so users won't be constantly downloading so users won't be constantly downloading plug-ins for different schemesplug-ins for different schemes..

More to the point for the library world: More to the point for the library world: library automation vendors need to know library automation vendors need to know what schemes they need to support. what schemes they need to support.

What’s Missing? What’s Missing? (continued)(continued)

A deployed mechanism for directing resolution A deployed mechanism for directing resolution requests to the appropriate resolver.requests to the appropriate resolver.

An effective technical infrastructure allowing An effective technical infrastructure allowing identifiers to be recognized and handled by identifiers to be recognized and handled by browsers. browsers.

A single document -- for example, A single document -- for example, a W3C a W3C technical report or, preferably, technical report or, preferably, a Recommendation a Recommendation -- that ties all -- that ties all the information together coherently, and the information together coherently, and recommends revision where appropriate.recommends revision where appropriate.

What is a URI? Two Views:What is a URI? Two Views:

URLURL• http:http:• ftp:ftp:• z39.50z39.50• …………....

URNURN• nbn:nbn:• hdl:hdl:

URC?URC?

Http:Http: ftp:ftp: hdl:hdl: tv:tv: urn:urn:

• nbn:nbn:• hdl:hdl:

New URI Interest GroupNew URI Interest Group

New W3C Proposal for a New W3C Proposal for a URI Interest URI Interest Group Group • within the Architecture Domain within the Architecture Domain

to: “Build and maintain shared understanding to: “Build and maintain shared understanding around URIs technology and specifications”around URIs technology and specifications”

mission: to be responsive to the needs of the mission: to be responsive to the needs of the W3C membership and WGs for information W3C membership and WGs for information about URI technology. about URI technology.

LC’s interest in WAILC’s interest in WAI

LC is a Federal AgencyLC is a Federal Agency

LC includes NLSBPH LC includes NLSBPH (National Library (National Library Service for the Blind and Physically Service for the Blind and Physically Handicapped)Handicapped)• Digital talking booksDigital talking books• Web-brailleWeb-braille

Information RetrievalInformation Retrieval

XML and ProtocolsXML and Protocols

• Z39.50?Z39.50?

Z39.50/RDF integrationZ39.50/RDF integration

• an RDF representation of Z39.50 attribute sets?an RDF representation of Z39.50 attribute sets?• align RDF and Z39.50 data models? align RDF and Z39.50 data models?

XML query language a Z39.50 query XML query language a Z39.50 query type?type?