Protege: How To Define Class Axioms
This video is about defining class axioms using Protégé, a free, open-source ontology editor and framework. Although the video deals with one specific tool, it [...]
Ordnance Survey Linked Data: A Simple Spatial Query
In this blog post, the author discusses the relative lack of spatial indexes for data in RDF triple stores, compared to data stored in GIS [...]
From a Wikipedia Page to the Corresponding DBpedia Page in One Click
This blog post contains a "scriplet" (i.e., a little bit of JavaScript code embedded in a link) which, if placed in a Web browser's "bookmarks" [...]
Databases: Graph vs. Relational
This video describes the differences between graph database models (such as RDF) and relational models (RDBMS). The narrator gives examples of when it would be [...]
How Does a Graph Database Differ From a Relational Database?
This video describes the difference between a graph database model (such as RDF) and the relational database model (RDBMS). Focuses on the increased efficiency of [...]
How Is SPARQL Different From SQL?
This video explains how the SPARQL query language differs from SQL. Highlighted is the ability of SPARQL to handle complex joins that would be too [...]
Ontologies and the Semantic Web
A video lecture introducing RDF Schema and OWL, with visible slides throughout. The concepts behind ontologies are also discussed in a general, schema-agnostic manner. Places [...]
Using Ordnance Survey Linked Data: A Python RDFLib Example
The author describes how he created a mashup of data.gov.uk and Ordnance Survey Linked Data using just the Python RDFLib library - no triple store [...]
Permanent Identifiers and Vocabulary Publication: purl.org and w3id
This blog post addresses concerns with the stability of purl for hosting permanent URIs. As a possible alternative, the author presents w3id.org, an effort launched [...]
Towards a Human Readable Maintainable Ontology Documentation
Ontology documentation is critical to support reuse, as it provides an overview of the terms of the ontology with examples, diagrams and their definitions. In [...]