Has been described as a ‘data commons’, or more usually a Web of Data.
Problem for machines to extract meaning. At present, the raw data is not really available.
Principles underpinning the technology
Step back a bit to HTML HTML web of documents doesn’t encourage re-use, reduce redundancy. Are network effects but could be much better.
Note this is a considerable simplification of the detail in danger of misleading. Linked data exploits semantically meaningful tagging to encourage re-use, reduce redundancy etc.
Uses predicate logic. Goes back to Aristotle. Conceptualises things, and the relationships between things
Copac a union catalogue Both successful JISC services running for many years now Locah is a research project – will have to see if go into service with LD interface
In hypertext web sites it is considered generally rather bad etiquette not to link to related external material. The value of your own information is very much a function of what it links to, as well as the inherent value of the information within the web page. So it is also in the Semantic Web. Remember, this is about machines linking – machines need identifiers; humans generally know when something is a place or when it is a person. BBC + DBPedia + GeoNames + Archives Hub + Copac + VIAF = the Web as an exploratory space
You can imagine the research benefits if these principle were applied to datasets of your own interest area. British Library example. Improves Google visibility. Already seeing traffic via data.archiveshub.ac.uk
The aggregation and merging of the Hub data sources is enabled by the use of linked data. Linked data can also provide enrichment by linking to other data sources such as dbpedia.
“ lower level” units interpreted in context of the higher levels of description Arguably “incomplete” without the contextual data. Relations are asserted, e.g. member-of/component-of But there is no requirement or expectation that data consumers will follow the links describing the relations
UKOLN is supported by: LOCAH Project and Considerations of Linked Data Approaches 29 th March 2011 JISC Managing Research Data International Workshop, Birmingham, UK Adrian Stevenson LOCAH Project Manager
“ The term Linked Data refers to a set of best practices for publishing and connecting structured data on the Web.”
“ the Semantic Web is the goal or end result… Linked Data provides the means to reach that goal”
From ‘ Linked Data: The Story So Far ’ - Heath, Bizer and Berners-Lee 2009
The goal of Linked Data is to enable people to share structured data on the Web as easily as they can share documents today. Bizer/Cyganiak/Heath Linked Data Tutorial, linkeddata.org
In essence, it marks a shift in thinking from publishing data in human readable HTML documents to machine readable documents. That means that machines can do a little more of the thinking work for us. http://www.linkeddatatools.com/semantic-web-basics
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We can then take items from one dataset and link them to items from other datasets
BBC VIAF DBPedia Archives Hub Copac GeoNames
BBC:Cranford VIAF:Dickens DBpedia: Gaskell Hub:Gaskell Copac:Cranford Geonames:Manchester DBpedia: Dickens Hub:Dickens The Linking benefits of Linked Data
Archives Hub Model (as at 14/2/2011) Archival Resource Finding Aid EAD Document Biographical History Agent Family Person Place Concept Genre Function Organisation maintainedBy/ maintains origination associatedWith accessProvidedBy/ providesAccessTo topic/ page hasPart/ partOf hasPart/ partOf encodedAs/ encodes Repository (Agent) Book Place topic/ page Language Level administeredBy/ administers hasBiogHist/ isBiogHistFor foaf:focus Is-a associatedWith level Is-a language Concept Scheme inScheme Object representedBy Postcode Unit Extent Creation Birth Death extent participates in Temporal Entity Temporal Entity at time at time product of in