On Tue, 22 Aug 2006 10:28:03 -0600, Larry Hunter wrote: > In my experience, many complex knowledge modeling projects benefit > from the use of metaclasses. For example, if the domain of a > relationship is limited to several specific classes, it makes sense > to model those classes as members of a particular metaclass (i.e., > one that supports a particular slot type). There are gyrations > one can do to avoid metaclasses
Yes, you cannot do such complex knowledge modelling, and that it is good thing. Having the possibilty to make such complex (meta, meta-meta...) models does not only complicate reasoning -- it complicates almost everything: GUIs, queries, ontology editors, optimized datastores and last but not least the process of ontology development and re-use itself. Giving the developers the possibilty of such constructs adds another degree of freedom to ontology development, resulting in even more diverse, incompatible and possibly faulty ontologies. cheers, Matthias
