Base Metrics
Base Metrics comprise of simple metrics, like the counting of classes, axioms, objects etc. So it shows the quantity of ontology elements. For these Metrics we chose:
Contents
Axiom
Axioms are basics statements of an ontology, they are used to obtain information about classes and properties. Thus they are used to connect classes and properties identifiers to their specification.
Logical axiom
These special kind of axioms are universally valid.
Class
Classes in ontologies are concepts. These classes can contain other classes or individuals. In OWL there a generally a Thing-Class, which is a universal class. So every user defined class is a SubClass of the Thing-Class
With this metric we count the classes, including the thing-class, to create a view on the quantity of classes.
Total class
Individuals
Individuals are the instances of the classes. This metric counts these instances, one class could have a set of instances.
Total Individual
Property
In OWL there are two types of properties:
Object property
Object properties link individuals to individuals.
Total Object property
Data property count
Other then the Object properties the Data properties link individuals to data values
