DNER Architecture Andy Powell, Liz Lyon UKOLN, University of Bath a.powell@ukoln.ac.uk Consultative...

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DNER ArchitectureAndy Powell, Liz LyonUKOLN, University of Bath

a.powell@ukoln.ac.uk

www.ukoln.ac.uk

Consultative group, Charity Centre, London

16 Feb 2001

UKOLN is funded by Resource: The Council for Museums, Archives and Libraries, the Joint Information Systems Committee (JISC) of the Higher and Further Education Funding Councils, as well as by project funding from the JISC and the European Union. UKOLN also receives support from the University of Bath where it is based.

Overview

• scope - what is the DNER?• functional model - builds on scenarios• entity model - what are we dealing with?• network systems architecture• discover• locate, request, deliver• other shared services

General questions

• please raise them!• is this a coherent view• what’s wrong?• what’s missing?• there are gaps - need to try and fill them• ...in this study or further work

• validate current thinking• raise issues generally• specifically, think about

•user-profiles•collection description•service description

• authentication?• thesauri/terminology• recommendations

The DNER...

• is a set of content• is an information environment that provides

secure and convenient access to that content• is comprehensive?• is managed?• complements institutional and other resources• weaves rich information resources into the fabric

of the Web

• provides cost-effective support for new modes of learning, research and communication

What’s in the DNER

• a national, strategicresource.

• licensed, created• available through data centres, ...

• a framework for access to a community resource• deposit - AHDS, data archive, ...• discovery - archives hub, COPAC, …• extend to local informational assets

• access to a quality controlled global resource • Resource Discovery Network, A&I services

Primary Content

Secondary Content

Funded

Institutional

External

Museum

home pages

research papers

Institutional gateways

Google Yahoo

tRDN A&I

imagesFull-textstatistics

Map data

Amazon

Public libraries

DNER content map

User view

• personalised landscape• own information foremost• …then

• institutional (Intranet/MLE)•external•DNER

• subject focus• media-type focus

Scope summary...

• stuff is…• local / remote•primary / secondary•digital / physical•policy controlled / non-policy controlled• in / out

• process includes•discover / locate and access•use / reuse / create• receive / provide

DNER Collections• content typically in the form of

‘collections’• collections of stuff (text, images, data, ...)• collections of metadata about stuff (e.g

subject gateway’s Internet Resource Catalogues)

• services make stuff available• people access stuff thru services

Primary DNER entities

Content

Person Service

Functional Model

Web Web Web Web Web

Currently...Content

End-user

Functional model

• think about what people are doing (or want to do) with the DNER

• based on MODELS verbs•discover, locate, request, deliver

• ...and later MODELS Information Architecture work

• addition of new verbs• modelled using UML• generic - applicable to finding Web

resources, buying books, buying cars, ...

High-level view

discover

locate

useRecord

request

deliver

useResource

enterinitiate

initiate

user provider

• discover, locate, request, deliver• enter, useRecord, useResource added• user-need -> item on desktop (virtual or physical)

and use

authenticate landscape<<use>><<use>>

initiate

user provider

• user visits Web service• login (using Athens - may have ‘guest’ account)• service builds personalised landscape (view of

available resources)

survey/discover

discoverinitiateuser provider

survey

savedList search

initiate

<<extend>>

savedList search

browse alert initiate

<<use>>queryAssist

• survey - high-level collection description search (narrows or widens landscape)

• discover - drill-down• same strategies used in each• user-need -> metadata about ‘work’ (book or article) or ‘item’ (Web

resource)

detail

locate format

initiate

user providerratings conditions initiate

• locate is instance of getting more ‘detail’ about a resource

• locations, formats, ratings, terms & conditions• metadata about ‘work’ -> metadata about ‘item’

useRecord

annotate

initiate

user providerremember share

• locate is instance of getting more ‘detail’ about a resource

• locations, formats, ratings, terms & conditions

• metadata about ‘work/item’ -> richer metadata about ‘work/item’ and location of ‘item’ or ‘delivery service’ for ‘item’

request/access

request

authorise

access

download deliver

initiate

initiateuser provider

• authorisation required before access• download (user initiated, e.g. clicking on link)• deliver (provider initiated, e.g. Amazon delivering book)• metadata about ‘work/item’ and location of ‘item’ or ‘delivery

service’ for ‘item’ -> item

useResource

incorporate

initiate

user providerview storeunpack process

useResource

• not thoroughly modelled here

• unpack - e.g. dealing with IMS package

• view - simplest case (looking at document)

• process - run software

• incorporate - embed into multimedia essay

• store, share, publish(?)

DNER information flow

discover

useRecorddetail

request

access

useResource

DNER information flow

• DNER not just a ‘provider to user’ flow• users are both recipients of and creators

of both primary and secondary content• DNER architecture needs to support

• collaboration•creation

• …as well as discovery, etc.• current work on architecture doesn’t really

address this. Does that matter?

Network Systems Architecture

Web Web Web Web Web

Currently...Content

End-user

Current services offer mix of survey, discover, detail, request, access, useRecord functionality

End-user needs to join services together manually as well as learning multiple user interfaces

Web Web Web Web Web

Currently...Content

End-user

Need to think about what shared services might be required to offer functionality

Also useful to think about what entities are being dealt with

authenticate landscape<<use>><<use>>

initiate

user provider

• Shared services• authentication• user-profiling• collection description• service description

• Entities

• person/role

• (group)

• (organisation)

• collection

• service

survey

user provider

survey

savedList search

initiate

<<extend>>

<<use>>queryAssist

• Shared services• collection description• thesauri/terminology

• Entities• collection

discover

savedList search<<use>>

queryAssist

• Shared services

• service description

• metadata registry

• terminology/thesauri

• Entities

• collection

• service

• schema

• work

• item

detail

locate format

initiate

user providerratings conditions initiate

• Shared services• locate• ratings• (terms & conditions)• service description

• Entities

• work

• item

• service

useRecord

annotate

initiate

user providerremember share

• Shared services

• (bookmark)• (annotation)

• Entities• work• item

request/access

request

authorise

access

download deliver

initiate

initiateuser provider

• Shared services• authorisation

• Entities

• item

• service

• person

useResource

incorporate

initiate

user providerview storeunpack process

useResource

• Shared services • Entities• item

discover

savedList search<<use>>

queryAssist

• Shared services

• service description

• metadata registry

• terminology/thesauri

• Entities

• collection

• service

• schema

• work

• item

DNER Entities

Service

PersonProfile Content

OrganisationGroup

accessesprovidesAccessTo

hasPart

isPartOfis

offershas

hasisMemberOf

fulfils

comprises

DNER shared services

• authentication• user-profiling• collection description• thesauri/terminology• metadata registry• service description• location (ratings, terms & conditions)• authorisation

Web Web Web Web

Currently...Content

End-user

Authentication

Web Web Web Web

Currently...Content

End-user

Authentication

Collectiondescription

User-profiling

Web Web Web Web

Shared service modelContent

End-user

Authentication

Authorisation

Collection Desc

Service Desc

Thesauri, ...

User-profile

Joining things together

• Framework for shared services• DNER as coherent whole rather than lots

of stand-alone services• two areas in particular• discovery

• finding stuff from multiple content providers

• locate/request/deliver• streamlining access

Discover

• services need to expose Web content for machine use

• m2m• expose metadata using search,

harvesting or alerting protocols• expose data in machine-readable and

persistent ways

Fusion?

• In order to remove need for end-user to discover across several individual services

• develop services that bring stuff together• fusion•portals•presentation services

• searching vs. sharing• alerting

Note: I don’t like these words!

Presentation services

• ...lots!?• subject portals• data centre portals• institutional portals• personal portals (agents)• virtual learning environments

Web Web Web Web

SearchingContent

End-user

Authentication

Authorisation

Collection Desc

Service Desc

Thesauri, ...

Presentation

User-profile

Z39.50Bath Profile

Web Web Web Web

SearchingContent

End-user

Authentication

Authorisation

Collection Desc

Service Desc

Thesauri, ...

Presentation

User-profile

Z39.50Bath Profile

brokers andgateways

Broker

Z39.50 - Bath Profile

• cross-domain focus (in part)• DC XML records• DTD-based rather than XML Schema

Web Web Web Web

SharingContent

End-user

Authentication

Authorisation

Collection Desc

Service Desc

Thesauri, ...

Presentation

User-profile

OpenArchivesInitiative

Web Web Web Web

SharingContent

End-user

Authentication

Authorisation

Collection Desc

Service Desc

Thesauri, ...

Presentation

User-profile

OpenArchivesInitiative

Aggregator

Open Archives Initiative

• OAI Metadata Harvesting Framework• simple mechanism for sharing metadata

records• records shared over HTTP...• ... as XML (using XML Schema)• client can ask metadata server for

• all records• all records modified in last ‘n’ days• info about sets, formats, etc.

• See <http://www.openarchives.org/>

Web Web Web Web

AlertingContent

End-user

Authentication

Authorisation

Collection Desc

Service Desc

Thesauri, ...

Presentation

User-profile

Aggregator

• Rich Site Summary• RDF Site Summary• XML application for syndicated news feeds• pointers and simple descriptions of news

items (not the items themselves)• has been transitioned to more generic

RDF/XML application (RSS 1.0)• no querying - just regular ‘gathering’ of RSS

filehttp://www.ukoln.ac.uk/metadata/rssxpress/

Active vs. passive alerting

• note that RSS is passive - presentation service or aggregator collects

• Email is active - content service delivers• can view email alerting as content service

‘agent’

Discovery issues

• Terminology - presentation services, portals, brokers, etc.

• protocols - are they right?• uptake - how many services will

implement Z? Does it matter?

Exposing single-item content

• for some (?) Web content there is one copy only - ‘single-item’

• need to expose that content in machine readable ways

• using HTTP and appropriate formats (see DNER Standards Document)

• Web pages, images, sounds, videos, etc.

Single-item identification

• For single-item resources, discovery process leads to identifier

• on the Web that is a URI (typically a URL)• need to persistently identify stuff

• enable lecturers to embed it into learning resources

• enable students to embed it into multimedia essays

• enable people to cite it• ... a current example (from VADS)

Content example

http://vads.ahds.ac.uk/ixbin/hixclient?_IXDB_=vads&_IXSPFX_=t&_MREF_=3392&_IXSR_=ea1&_IXSP_=0&_IXSS_=%2524%2brec%2bvads%2band%2bseaside%2band%2b%2528%2528Basic%2bDesign%2bCollection%2bin%2btitle_vads_collection%2529%2bor%2b%2528Halliwell%2bCollection%2bin%2btitle_vads_collection%2529%2bor%2b%2528Imperial%2bWar%2bMuseum%2bConcise%2bArt%2bCollection%2bin%2btitle_vads_collection%2529%2bor%2b%2528London%2bCollege%2bof%2bFashion%2bCollege%2bArchive%2bin%2btitle_vads_collection%2529%2529%2bsort%2btitle%2b%3d%252e%26_IXDB_%3dvads&_IXRECNUM=3392&_IXASEARCH=&SUBMIT-BUTTON=DISPLAY

Content example - the URL

Be nicer if...

• ...content URL was something like:

http://vads.ahds.ac.uk/id=137234-849783

http://dx.doi.org/10.3456/1096493

Identifiers

• what is identified...?• the resource (image, text, map, data,

sound, ...)• the resource in context (e.g.

embedded into VADS page)• metadata about the resource (e.g.

from subject gateway)

Identifiers

• could use URLs, PURLs, DOIs, ... but...• URLs, locators not identifiers• DOIs and PURLs resolved centrally• all resolve to same thing irrespective of

who/where the user is. E.g.• 10.1045/october2000-granger always resolves

to US version even though D-Lib mirrored in UK• http://purl.org/dc always resolves to US version

even though DC pages mirrored in UK

• DOI and PURL resolved thru US resolver

Web content - issues

• Need guidelines on good practice for using URIs?

• Need to investigate possibilities for use of DOIs?

• Other suggestions?

locate, request, deliver

Multiple-item content

• For mutiple-item content, need to move from discovery thru locate, request and access

• move from generic ‘work’ to particular ‘item’

• find appropriate copy• location is context sensitive - need to

know who, where end-user is• best carried out locally to end-user?

Physical content

• discover typically results in metadata about the ‘work’ or a global identifier (ISBN or ISSN)

• in other words, a citation for the resource• need to encode citation in machine

readable way• need to resolve citation in context

sensitive way

Locate and identifiers

Discover

Locate

Request

Item URL

URI DOI

OpenURL or Z39.50 request

Citation/metadata

Discovery services

Web resource BookJournal issue Article

Delivery service URLor

Item URL

Locate services

Persistent ‘identifiers’- context independent

Transient ‘locators’- context sensitive

OpenURL

• OpenURL - way to encode citation for a resource

• OpenURL = BaseURL + Description• BaseURL = http://sfx.bath.ac.uk/sfxmenu• Description = Origin + ObjectDescription• ObjectDescription is either a global

identifier (e.g. A DOI) or a description (a citation) or a local identifier of some kind

• http://sfx.bath.ac.uk/sfxmenu?genre=book&isbn=1234-5678

OpenURL resolver

Content

End-user

OpenURL

resolver

Deliveryservice

Locate APIs

• Going into a locate service (from discover)•URI•OpenURL (metadata and/or identifier)•Z39.50 (Bath Profile) query

• Coming out of locate service (into request)•URL for item•URL for delivery service for item (e.g. Amazon order form or ILL form)

Locate and useRecord

• useRecord (I.e. adding record to reading list of bookmarks) should use the URI or OpenURL from discover•persistent• context indenpendent

• *not* the URL from locate• but browser will display the locate URL in

its location box - so users are likely to use it?

Other shared services

DNER shared services

• authentication• authorisation• user-profiling• collection description• thesauri/terminology• metadata registry• service description• location (ratings, terms & conditions)

User-profile

• Schema•LIP, eduPerson

• protocol•LDAP, XML/HTTP, SOAP

• ownership•?

• delivery•central service?• institutional service?•user service?

Collection description

• Schema•RSLP, eLib

• protocol•LDAP, XML/HTTP, SOAP

• ownership•?

• delivery•central service?•content provider service?•search or share?

Service description

• Schema•UDDI, Explain, Explain-Lite

• protocol•SOAP, XML/HTTP

• ownership•?

• delivery•central service?•service service?•search or share?

Thesauri/terminology

Authentication

• ...and authorisation

Other services

• linkbasket• annotation• ratings• terms & conditions

DNER Architecture Andy Powell, Liz Lyon UKOLN, University of Bath a.powell@ukoln.ac.uk Consultative...

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