Abstract: A method and system facilitating multiple independent extensions of a concept taxonomy. Separate classification operations determine how one or more distinct sets of additional concepts, each comprising an extension, fit in with the original taxonomy while leaving the original taxonomy intact and substantially without copying it. Classification results are recorded so that the original taxonomy and every extension thereof can be independently queried and retrieved on demand. This process is referred to as modular classification.

Abstract: In response to the users actions relative to graphical representations of a multiple inheritance concept hierarchy to delete, add or modify the relationships between the various concepts, property declaration, property constraints and relationships therebetween, this system first, recognizes and disambiguates possible semantic incoherance introduced by the changes; second, suggests alternative procedures to ameliorate any perceived incoherence; third, interactively allows an agent (user or machine) to select from one of the alternatives; and fourth, performs the sequence of necessary operations to resolve semantic incoherence in the modified hierarchy.