Evolution of faceted taxonomies and CTCA expressions

摘要

A faceted taxonomy is a set of taxonomies each describing the application domain from a different (preferably orthogonal) point of view. CTCA is an algebra that allows specifying the set of meaningful compound terms (meaningful conjunctions of terms) over a faceted taxonomy in a flexible and efficient manner. However, taxonomy updates may turn a CTCA expression e not well-formed and may turn the compound terms specified by e to no longer reflect the domain knowledge originally expressed in e. This paper shows how we can revise e after a taxonomy update and reach an expression e′ that is both well-formed and whose semantics (compound terms defined) is as close as possible to the semantics of the original expression e before the update. Various cases are analyzed and the revising algorithms are given. The proposed technique can enhance the robustness and usability of systems that are based on CTCA and allows optimizing several other tasks where CTCA can be used (including mining and compressing).