  Emerging ontology authoring methods to add knowledge to an ontology focus on
ameliorating the validation bottleneck. The verification of the newly added
axiom is still one of trying and seeing what the reasoner says, because a
systematic testbed for ontology authoring is missing. We sought to address this
by introducing the approach of test-driven development for ontology authoring.
We specify 36 generic tests, as TBox queries and TBox axioms tested through
individuals, and structure their inner workings in an `open box'-way, which
cover the OWL 2 DL language features. This is implemented as a Protege plugin
so that one can perform a TDD test as a black box test. We evaluated the two
test approaches on their performance. The TBox queries were faster, and that
effect is more pronounced the larger the ontology is. We provide a general
sequence of a TDD process for ontology engineering as a foundation for a TDD
methodology.
