
Ontology Engineering 317
aspects of the domain or maybe an upper-level ontology (an ontology cover-
ing the most general concepts of a domain or even of everything) can be used
and extended by more specific information.
While extending one given ontology by more information (or pruning it) is
arguably more or less straightforward, problems usually arise as soon as two or
more formerly independent ontologies are involved and have to be reconciled.
They might rely on different ways of modeling, on different naming schemes,
or even on different modeling languages.
No matter whether s everal source ontologies are to be integrated into one
(ontology merging)