DNER ArchitectureAndy PowellUKOLN, University of Batha.powell@ukoln.ac.ukwww.ukoln.ac.uk

JOIN-UP Seminar on Linking Technologies, Edinburgh6 March 2001UKOLN 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.

What is the DNER?DNER is an information environment (a set of services) that enables people to access and use a wide variety of resourcesresources areservices / contentlocal / remoteprimary / secondary, data / metadatadigital / physicalJISC funded / not JISC fundedpolicy controlled / non-policy controlledaccess and use includesdiscover / locate / accessuse / reuse / createreceive / provide / collaborate

Functional modelmove from user-need to resource on desktop (physical or digital)three stage discovery processlandscape and survey - collection leveldiscover and detail - item leveliterative processfinal detail phase provides information about how to request instance of resourcedetail may involve resolving identifier or metadata for resource using resolversurveydiscoverauthenticatelandscapedetailrequestauthoriseaccessuseResourceuseRecord

DNER information flowprocess is iterative at all stagesDNER not just a provider to user flowusers are both recipients of and creators of both primary content, secondary content and metadataDNER architecture needs to supportcollaboration andcreationas well as discovery, etc.however, current work on architecture doesnt really address this.

Systems architectureframework for network of shared servicesDNER as coherent whole rather than lots of stand-alone servicestwo areas in particular...discoveryfinding stuff from multiple content providerslocate/request/deliverstreamlining access

Discoverin order to allow end-user to discover seamlessly across several network services...services need to expose content for machine use (m2m)expose metadata forsearchingharvestingalertingdevelop services that bring stuff togetherportals

Portalsportals provide access to multiple network servicesthere will be many kinds of portals...subject portalsdata centre portalsinstitutional portalspersonal portals (agents)virtual learning environmentsthin portals (shallow linking)thick portals (deep linking - search, share and alert)

Thin portalWebWebWebWebContentEnd-userPortalAuthenticationAuthorisationCollectn DescHTTP

Thick portal - searchingWebWebWebWebContentEnd-userPortalZ39.50Bath ProfileBrokerAuthenticationAuthorisationCollectn DescService DescHTTP

Searching and Z39.50cross-searching based on Z39.50 and Bath Profilepragmatic rather than dogmatic choiceZ39.50 only real option at this stagecan move to other options (e.g. W3C query language) when appropriate

Thick portal - sharingWebWebWebWebContentEnd-userPortalOpenArchivesInitiativeAggregatorAuthenticationAuthorisationCollectn DescService DescHTTP

Open Archives InitiativeOAI Metadata Harvesting Frameworksimple mechanism for sharing metadata recordsrecords shared over HTTP...... as XML (using XML Schema)client can ask metadata server forall recordsall records modified in last n daysinfo about sets, formats, etc.See

Thick portal - alertingWebWebWebWebContentEnd-userPortalRSSAggregatorEmailAuthenticationAuthorisationCollectn DescService DescHTTP

RSSRich/RDF Site SummaryXML application for syndicated news feedspointers 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/

Resource identificationdiscovery results in metadata about a resource that may include its identifier or a locatorfor Web resources a URL is commonidentifier is persistentlocator also needs to be persistentenable lecturers to embed it into learning resourcesenable students to embed it into multimedia essaysenable people to cite it

Identifiers/locatorsalso need to think about what is identified...?the resource (e.g. an image)the resource in context (e.g. image embedded into VADS page)metadata about the resource (e.g. description of image from VADS or subject gateway)probably need to identify all of theseneed guidelines on good practice for use of URLsinvestigate use of DOIs

Resolving identifiersmay need to resolve the metadata, identifier or locator into information about how to request a particular instance of the resourceneed to find appropriate copyresolution is context sensitive - need to know who end-user is, where they are and what they have access tomay be best carried out locally to end-user?

OpenURLmetadata, identifier or locator effectively forms a citation for the resourceOpenURL provides mechanism for encoding citation for a resource as a URLOpenURL = baseURL + descriptionbaseURL provides location of a resolverdescription is either a global identifier (e.g. a DOI or ISBN) or a description (a citation) or mixturehttp://sfx.bath.ac.uk/sfxmenu?genre=book&isbn=1234-5678

Locate and identifiersDiscoverLocateRequestISBN

ResourceURLURIDOIOpenURL or Z39.50 requestCitation/metadataDiscovery servicesWeb resourceBookJournal issueArticleDelivery service URLorResource URLLocate services(resolvers)Persistent identifiers- context independentTransient locators- context sensitive

OpenURL resolverContentEnd-userDeliveryserviceAuthenticationAuthorisationCollectn DescService DescPortalOpenURLHTTPResolver

DNER shared servicesauthenticationauthorisation/profilingcollection descriptionservice descriptionresolutionuser preferencesthesauri/terminologymetadata registry(ratings, terms & conditions)keydesirable

Summarysharedservicesportalscontentbrokersandaggregatorsprovisionfusionmiddlewarepresentationm2minterfaces