Semantic Web Training

The first tutorial for the Web Ontology Language and the Protégé ontology editor developed at Stanford University was the Pizza tutorial. Pizza was chosen as a domain most people and all developers were familiar with due to late night meals to fuel them through long nights of coding to make deadlines. The original tutorial was enhanced by Michael DeBellis to support a workshop in India. The original tutorial was significantly out of step with the revised Protege user interface. Mr. DeBellis updated the user interface and added new chapters for SPARQL, SWRL, SHACL, and Web Protege. Mr. DeBellis's revised tutorial has been used by many industry groups and university classes as an introduction to OWL and the Semantic Web with Protégé . 

One of the differences between property graphs such as Neo4j and the Web Ontology Language is property graphs allow developers to add attributes to a property. This is not possible with OWL. However, the n-ary relation pattern is one of many patterns imported from the Object-Oriented community that allows not just attributes but properties on relations by creating a class to model the relation. This is known as "reifying" the relation. 

One thing that often confuses new users of OWL is the concept of puns. This article describes what they are and why we need them. 

There are constructs in OWL to declare that two classes or instances are in fact the same logical entity. This is a powerful and useful feature. However, new users can often misuse it. This article explains why it is usually better to use the SKOS  alt and pref label properties for most synonym use cases and clarifies when it is useful to use features such as owl:sameAs.