Glossary

Fuseki

Part of the Apache Jena project, Fuseki is Free Software bringing together a triple store, a SPARQL implementation, and the graph store HTTP protocol. The Open Data Service uses Fuseki for storing and mediating access to the available data.

linked data

A pattern for publishing data on the web using URIs as identifiers, so that it can be interlinked and thus gain greater utility by becoming part of the web of data (by analogy to the human-readable web of documents). See the Wikipedia article for more information.

If you’re just getting started with linked data, the Open Data Team at Southampton have put together this useful guide for beginners.

N-Triples

A simple RDF serialization, and a subset of Turtle (i.e. every N-Triples file is also valid Turtle). Often used for streaming RDF data between systems. See the Wikipedia page for more information.

open data stars

The stars represent the extent to which a dataset is part of the linked open data web. These were the definitions used by Tim Berners-Lee during his Gov 2.0 talk in 2010, and have since become widely accepted as an ideal to work towards.

	Data available, but not openly licensed
	Put your data on the web with an open licence (in any format)
	Make it available in a machine readable format (i.e. no image scans!)
	Use a open, standard format (eg JSON)
	Use an open, linked data format (URIs for everything so people can point to your data)
	Link your data to other people’s data

RDF

See Resource Description Framework.

RDF serialization

As RDF is just a data model, it doesn’t have any one true concrete syntax. RDF triple serializations include:

• RDF/XML
• Turtle
• N-Triples
• RDF/JSON

RDF/JSON

A serialization of RDF into JSON. See the documentation for more information.

RDF/XML

A serialization of RDF into XML. Generally not considered pretty, but useful when creating RDF using XML tools. For more information, see this explanation of it’s “stripedness” and the format specification.

Examples of RDF/XML can be found here and here.

Resource Description Framework

The Resource Description Framework (RDF) is a metadata data model based around subject object predicate triples. RDF is not tied to representing any particular type of information, leading to an information infrastructure that works for just about anything.

RDF is generally queried using SPARQL. You can read more about RDF at the W3C and Wikipedia.

slug

A relatively short, human-readable sequence of characters used to uniquely identify a thing, normally in a URI or URL. These should normally be lowercase with punctuation removed, and hyphens used to delimit words if applicable. Examples include course, undergraduate-course, and university-of-oxford. Often one excludes terms such as “the” and “and” as they add unnecessary length to the slug. See the Clean URL page on Wikipedia for more information.

slugification

Turning a phrase into a slug. For example, one would slugify “University of Oxford” to university-of-oxford. Slugification can either be done automatically, or with human input.

SPARQL

A query language for RDF databases. SPARQL queries can return table-like results (like SQL SELECT queries), or RDF.

Cambridge Semantics’ SPARQL by Example provides a good introduction to the language. answers.semantic.web is also a good resource if you get stuck.

The Open Data Service supports all of SPARQL 1.1 through Jena ARQ.

triple

An atom of information in RDF <Resource Description Framework>. A triple consists of a subject, predicate and object, such as “Alice (S) knows (P) Bob (O)”. These units of information are then composed to produce.

triple store

A triple store is a database for storing RDF. See the Wikipedia article for more information.

Turtle

An RDF serialization which is generally found to be more comprehensible to humans than RDF/XML. See the Wikipedia article for a more in-depth explanation.

URI

In RDF, URIs (Uniform Resource Identifiers) are used to refer to both documents on the web (web pages, images, etc) and things. By each being globally unique we are able to create a commonly vocabulary in which to describe the world around us. See the Wikipedia section on resource identification for more information.

vocabulary

A set of URI terms that have a commonly-understood interpretation and so can be used to describe things in RDF. A vocabulary generally has one particular focus, e.g. describing organisations, relationships, or offers to sell products. There are sites such as Schemapedia and prefix.cc which help with finding vocabularies.