The key characteristics of the ontologies are
displayed in Table 1. The number of classes,
individuals, and properties of an ontology are only
relevant in the degree to which they are used.
Therefore, we have selected to present different
views of these characteristics. The numbers of
classes, individuals, and properties are divided
into two different views where n is the number
when no reasoner was used and r is the number
when a reasoner was used. For instance, the Travel
ontology is seen as having 34 classes without using
a reasoner while 33 when using a reasoner. The
Travel ontology contains a 'Safari' class that is a
sub-class of both the 'Adventure' class and the
'Sightseeing' class. Further, when using a reasoner the representation of the 'Safari' entity is not OWL
DL compliant and hence omitted, which results in
33 versus 34 classes.