You don't have to know anything about linked data and the underlying technologies to make use of the controlled lists in the Local Government Business Model (LGBM). You can view them online and download them as Word documents, spreadsheets and in esd-toolkit's standard XML format. But if you want to use semantic web techniques to exploit LGBM and link to linked data elsewhere on the web, read on...
When data is expressed on web servers across the Internet as linked data, it may be treated as one giant database that can be queried with the SPARQL language in just the same way as the Structured Query Language (SQL) can be used to query a traditional database. For this to work linked data is expressed in the Resource Description Format(RDF)according to documented ontonolies.
esd offers a SPQRQL end point for querying its linked data at http://doc.esd.org.uk/sparql.ashx. A form showing a sample query and allowing you to test your own SPARQL query is given at: http://doc.esd.org.uk/sparqlform.aspx. Please bear in mind that we are at an early stage of development, do not run queries that place a heavy load on our servers (or we may need to limit access to the service) and e-mail support@esd.org.uk if you have problems. Note that SPARQL server only supports queries run against triples held in esd's triple store database. It does not support joins with the data on external servers at present.
SKOS
All controlled lists maintained by esd-toolkit are expressed in the W3C Simple Knowledge Organization System (SKOS) RDF format.
Each controlled list is a SKOS Concept Scheme. Each item within a controlled list is a SKOS Concept. Each conceptscheme and concept has many properties as defined by SKOS and Dublin Core.
Concepts have one preferred label and any number of alternative labels.
For concepts in each list, esd creates its own RDF classes which are sub-classes of the SKOS concept. For example, the Service List includes concepts of the type defined by esd as service a Service class. These classes may have extra properties beyond those that apply to every SKOS concept.
Mappings between lists are defined by esd. For example where a service is required by a legal duty, this is expressed by the requiresService property.
URIs and how they are defined
Every list, list item and property, including mappings between list items, is given a Unique Resource Identifier (URI).
URIs are defined according to the UK Cabinet Office document Designing URI Sets for the UK Public Sector which draws on the W3C document Cool URIs for the Semantic Web.
Important things to note are:
- URIs all begin with http:// and so they can be resolved over the Web
- URIs for things (eg lists and list items) all begin with http://id.esd.org.uk/
- If you access URIs beginning with http://id.esd.org.uk/ from a normal web browser, you will be redirected to a page whose address starts with http://doc.esd.org.uk/ documenting the thing whose id you used. If you access the same URIs from something that can read RDF (or you change the end of a doc page address to ".rdf") you will get an RDF description of the thing
- Classes and properties defined by esd have URIs that start with http://def.esd.org.uk/
We provide links to external URIs (eg those defined by SKOS and Dublin Core), which do not necessarily follow the above rules.