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DNER ArchitectureAndy Powell, Liz LyonUKOLN, University of Bath
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.
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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
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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
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Aims
• validate current thinking• raise issues generally• specifically, think about
•user-profiles•collection description•service description
• authentication?• thesauri/terminology• recommendations
Scope
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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
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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
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Primary Content
Secondary Content
Funded
Institutional
External
Web
pag
es
Museum
s
home pages
thes
es
research papers
OPACs
Institutional gateways
Google Yahoo
No
rthe
rnL
igh
tRDN A&I
imagesFull-textstatistics
Map data
COPAC
Amazon
Public libraries
cour
sew
are
DNER content map
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User view
• personalised landscape• own information foremost• …then
• institutional (Intranet/MLE)•external•DNER
• subject focus• media-type focus
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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
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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
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Primary DNER entities
Content
Person Service
Functional Model
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Web Web Web Web Web
Currently...Content
End-user
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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, ...
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High-level view
discover
locate
useRecord
request
deliver
useResource
enterinitiate
initiate
initiate
initiate
initiate
initiate
initiate
user provider
• discover, locate, request, deliver• enter, useRecord, useResource added• user-need -> item on desktop (virtual or physical)
and use
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enter
enter
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)
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survey/discover
discoverinitiateuser provider
survey
savedList search
initiate
<<extend>>
savedList search
browse alert initiate
<<use>>queryAssist
<<use>>queryAssist
browse alert initiate
• 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)
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detail
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’
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useRecord
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’
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request/access
request
authorise
access
download deliver
initiate
initiate
initiate
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
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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(?)
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DNER information flow
discover
useRecorddetail
request
access
useResource
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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
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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
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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
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enter
enter
authenticate landscape<<use>><<use>>
initiate
user provider
• Shared services• authentication• user-profiling• collection description• service description
• Entities
• person/role
• (group)
• (organisation)
• collection
• service
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survey
user provider
survey
savedList search
initiate
<<extend>>
browse alert initiate
<<use>>queryAssist
• Shared services• collection description• thesauri/terminology
• Entities• collection
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discover
discoverinitiateuser provider
savedList search<<use>>
queryAssist
browse alert initiate
• Shared services
• service description
• metadata registry
• terminology/thesauri
• Entities
• collection
• service
• schema
• work
• item
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detail
detail
locate format
initiate
user providerratings conditions initiate
• Shared services• locate• ratings• (terms & conditions)• service description
• Entities
• work
• item
• service
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useRecord
useRecord
annotate
initiate
user providerremember share
• Shared services
• (bookmark)• (annotation)
• Entities• work• item
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request/access
request
authorise
access
download deliver
initiate
initiate
initiate
initiate
initiateuser provider
• Shared services• authorisation
• Entities
• item
• service
• person
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useResource
incorporate
initiate
user providerview storeunpack process
useResource
• Shared services • Entities• item
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discover
discoverinitiateuser provider
savedList search<<use>>
queryAssist
browse alert initiate
• Shared services
• service description
• metadata registry
• terminology/thesauri
• Entities
• collection
• service
• schema
• work
• item
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DNER Entities
Service
PersonProfile Content
OrganisationGroup
accessesprovidesAccessTo
hasPart
isPartOfis
owns
offershas
hasisMemberOf
Role
fulfils
comprises
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DNER shared services
• authentication• user-profiling• collection description• thesauri/terminology• metadata registry• service description• location (ratings, terms & conditions)• authorisation
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Web Web Web Web
Currently...Content
End-user
Authentication
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Web Web Web Web
Currently...Content
End-user
Authentication
Collectiondescription
User-profiling
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Web Web Web Web
Shared service modelContent
End-user
Authentication
Authorisation
Collection Desc
Service Desc
Thesauri, ...
User-profile
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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
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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
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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!
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Presentation services
• ...lots!?• subject portals• data centre portals• institutional portals• personal portals (agents)• virtual learning environments
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Web Web Web Web
SearchingContent
End-user
Authentication
Authorisation
Collection Desc
Service Desc
Thesauri, ...
Presentation
User-profile
Z39.50Bath Profile
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Web Web Web Web
SearchingContent
End-user
Authentication
Authorisation
Collection Desc
Service Desc
Thesauri, ...
Presentation
User-profile
Z39.50Bath Profile
brokers andgateways
Broker
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Z39.50 - Bath Profile
• cross-domain focus (in part)• DC XML records• DTD-based rather than XML Schema
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Web Web Web Web
SharingContent
End-user
Authentication
Authorisation
Collection Desc
Service Desc
Thesauri, ...
Presentation
User-profile
OpenArchivesInitiative
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Web Web Web Web
SharingContent
End-user
Authentication
Authorisation
Collection Desc
Service Desc
Thesauri, ...
Presentation
User-profile
OpenArchivesInitiative
Aggregator
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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/>
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Web Web Web Web
AlertingContent
End-user
Authentication
Authorisation
Collection Desc
Service Desc
Thesauri, ...
Presentation
User-profile
RSS
Aggregator
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RSS
• 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/
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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’
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Discovery issues
• Terminology - presentation services, portals, brokers, etc.
• protocols - are they right?• uptake - how many services will
implement Z? Does it matter?
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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.
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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)
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Content example
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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
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Be nicer if...
• ...content URL was something like:
http://vads.ahds.ac.uk/id=137234-849783
http://dx.doi.org/10.3456/1096493
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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)
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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
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Web content - issues
• Need guidelines on good practice for using URIs?
• Need to investigate possibilities for use of DOIs?
• Other suggestions?
locate, request, deliver
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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?
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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
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Locate and identifiers
Discover
Locate
Request
ISBN
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
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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
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OpenURL resolver
Content
End-user
OpenURL
resolver
Deliveryservice
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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)
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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
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DNER shared services
• authentication• authorisation• user-profiling• collection description• thesauri/terminology• metadata registry• service description• location (ratings, terms & conditions)
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User-profile
• Schema•LIP, eduPerson
• protocol•LDAP, XML/HTTP, SOAP
• ownership•?
• delivery•central service?• institutional service?•user service?
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Collection description
• Schema•RSLP, eLib
• protocol•LDAP, XML/HTTP, SOAP
• ownership•?
• delivery•central service?•content provider service?•search or share?
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Service description
• Schema•UDDI, Explain, Explain-Lite
• protocol•SOAP, XML/HTTP
• ownership•?
• delivery•central service?•service service?•search or share?
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Thesauri/terminology
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Authentication
• ...and authorisation
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Other services
• linkbasket• annotation• ratings• terms & conditions
