Linked Data – the long and

winding road

Andy Powell, Eduserv

@andypowe11

Linked Data – the future of knowledge organisation on the Web, London14 Sept 2010

today’s topic...Linked Data: the future of knowledge

organisation on the Web...pre-supposes that Linked Data is the future of the Weband for that to be true, we have to understand the challenges we face in making it a reality

a storyabout the history of the Dublin Core initiativeand what that history tells us about the challenges for Linked Datait’s a largely non-technical story (superficial?)

about me...

long association with both Dublin Core

and RDFmore immersed in former

than lattermember of both the DC

Usage Board and the Advisory Board

previous chair of theDC Architecture WG

lead author of the originalDCMI Abstract Model

15What is DC?

Dublin Core (DC) is a metadata standard that provides a vocabulary for describing the "core" attributes of resources, most often in the context of resource discovery on the Web

• ~60 properties and classes within well curated vocabulary maintenance environment

• declared using RDF/RDFS

how did we get here?work on DC started in 1995 with 12 (later 15) ‘metadata elements’remember what the web was like in 1995?a library approach to resource discoverydescriptive records embedded into web pages – using the HTML ‘meta’ taga focus on ‘document like objects’librarian-centric

what impact has that had on DC?

a record centric approachshipping records from A to B

and the ‘record’ as mechanism for tracking provenance

• broad semantics• 15 ‘fuzzy

buckets’

a hang-over from days of library catalogue card – on which notes could be written?

flat-world modelling1:1 principle - the principle whereby

related but conceptually different entities, for example a painting and a

digital image of the painting, are described by separate metadata

recordsc.f. use of dc:creator in practice

Strings vs. things

little abstraction of the model...from the ‘syntax’actually little shared understanding of the underlying model

addition of the modelfirstly using the analogy of a language ‘grammar’then thru the development of the ‘Dublin Core Abstract Model’then thru the addition of the ‘Application Profile’essentially the RDF model

what have been the challenges of bringing the RDF model to the DC community?

Selling an ‘open world’ view...selling an open-world view

the ‘http’ URI problem

the ‘http’ URI problem

modelling...

modelling

http://blogs.ecs.soton.ac.uk/webteam/2010/09/02/the-modeler/

so...

my contention is that if Linked Data has a role to play in the future of knowledge organisationthen Linked Data must be successful on the Weband that means that RDF must be successful on the Web

DC brings a useful vocabulary of ‘core’ properties and classes

the history of DC helps us understand the challenges:

•easing the pain of modelling

•understanding http URIs and how they can be

managed•working within an ‘open

world’ view

also that DC brings some important functional requirements to the Linked Data (RDF) world• ‘boundedness’ (graphs, named

graphs, records) particularly to support provenance

• ‘constraints’ on those bounded graphs to support communities of practice

Thank youThank you

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