Presentation on theme: "DNER Architecture Andy Powell UKOLN, University of Bath Web of Science Enhancements Committee, Centre Point 5 March."— Presentation transcript:
DNER Architecture Andy Powell UKOLN, University of Bath Web of Science Enhancements Committee, Centre Point 5 March 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.
2 Contents scope functional model network systems architecture discover request, access
Scope What is the DNER?
4 Primary Content Secondary Content Funded Institutional External Web pages Museums home pages theses research papers OPACs Institutional gateways Google Yahoo Northern Light RDN A&I images Full-text statistics Map data COPAC Amazon Public libraries courseware DNER scope by content? WoS
5 but... … not a user view … not an institutional view user view based on personalised landscape... own information foremost institutional (intranet or VLE) DNER and external (general Web stuff) probably with discipline or subject focus … difficult to scope DNER by content?
6 Information environment DNER is an information environment (a set of services) that enables people to access and use a wide variety of resources ‘resources’ are… services / content local / remote primary / secondary, data / metadata digital / physical JISC funded / not JISC funded policy controlled / non-policy controlled ‘access and use’ includes discover / locate / access use / reuse / create receive / provide / collaborate
Functional Model What does the DNER do?
8 Web Currently... Content (local and remote) End-user end-user has to interact with several different services, each with their own user-interface what functional model is supported? what can end-user do?
9 Functional model move from user-need to resource on desktop (physical or digital) three stage ‘discovery process’ ‘landscape’ and ‘survey’ - collection level ‘discover’ and ‘detail’ - item level iterative process final ‘detail’ phase provides information about how to request instance of resource ‘detail’ may involve resolving identifier or metadata for resource using ‘resolver’ survey discover authenticate landscape detail request authorise access useResource useRecord
10 DNER information flow process is iterative at all stages DNER not just a ‘provider to user’ flow users are both recipients of and creators of both primary content, secondary content and metadata DNER architecture needs to support collaboration and creation …as well as discovery, etc. current work on architecture doesn’t really address this.
Network Systems Architecture How does the DNER do it?
12 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
13 Joining things together build 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
14 Discover in order to allow end-user to discover seamlessly across several network services... services need to expose content for machine use (m2m) expose metadata for searching harvesting alerting develop services that bring stuff together portals
15 Portals portals provide access to multiple network services there will be many kinds of portals... subject portals data centre portals institutional portals personal portals (agents) virtual learning environments thin portals (shallow linking) thick portals (deep linking, richer discovery and use functionality)
17 Web Searching Content End-user Portal Z39.50 Bath Profile Broker Authentication Authorisation Collect’n Desc Service Desc HTTP
18 Web Sharing Content End-user Portal Open Archives Initiative Aggregator Authentication Authorisation Collect’n Desc Service Desc HTTP
19 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
20 Web Alerting Content End-user Portal RSS Aggregator Authentication Authorisation Collect’n Desc Service Desc HTTP
21 RSS Rich/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 file
request, access How does the DNER help us access content?
23 Resource identification discover phase results in metadata about a resource that may include its identifier or a locator for Web resources a URL is common identifier is persistent locator also needs to be persistent enable lecturers to embed it into learning resources enable students to embed it into multimedia essays enable people to cite it
24 Identifiers/locators also 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 these need guidelines on good practice for use of URLs investigate use of DOIs
25 Resolving identifiers may need to resolve the metadata, identifier or locator into information about how to request a particular instance of the resource ‘locate’ part of detail phase provides resolution using resolvers resolvers find appropriate copy location is context sensitive - need to know who end-user is, where they are and what they have access to may be best carried out locally to end- user?
26 OpenURL metadata, identifier or locator forms a ‘citation’ for the resource OpenURL provides mechanism for encoding citation for a resource as a URL OpenURL = baseURL + description baseURL provides location of a ‘resolver’ description is either a global identifier (e.g. a DOI or ISBN) or a description (a citation) or mixture &isbn=
27 Locate and identifiers Discover Locate Request ISBN Resource URL URIDOI OpenURL or Z39.50 request Citation/metadata Discovery services Web resource Book Journal issue Article Delivery service URL or Resource URL Locate services (resolvers) Persistent ‘identifiers’ - context independent Transient ‘locators’ - context sensitive
28 OpenURL resolver Content End-user Delivery service Authentication Authorisation Collect’n Desc Service Desc Portal OpenURL HTTP Resolver