Introduction

Partitioning Classes (PTCL)

Introduction

In ontology engineering, abstract or concrete objects of a knowledge domain are organized in class hierarchies and relationship type hierarchies that arise through inheritance. The more general an entity is, the higher it appears in the hierarchy, the more specific an entity, the lower it appears. Special relationship types such as ‘phase’, ‘type’, ‘child’, ‘group’, ‘category’, ‘part’, etc. further divide the entities of a type into partitions. For example, vehicles can be partitioned according to their motor type, or employees of a company can be partitioned according to their roles. Objects are divided into disjunctive sets that are characterized by the equality of one or more attribute values. Such facts can be described in natural language by sentences like: “Mammals are warm-blooded”, or “Chameleons and octopuses can have multiple skin colors and change them”, or “Humans and birds have 2 legs”, or “Humans do not have feathers” or “Carl Linnaeus is deceased”. We see the task as finding an ontological form of expression that accurately describes these things and is at the same time short, concise, and easy to learn.

To this end, we introduce partitioning classes that occupy higher positions in the ontology hierarchy, serving as superclasses or overarching categories that help structure the ontology. They can define broad divisions or partitions within the domain, with extensions of regular classes positioned within these partitions based on their properties or relationships. Regular classes, on the other hand, can exist at different levels of the ontology hierarchy without necessarily serving as partitioning elements.

The key research question is: How can we design a methodology that provides a unified and standardized view of knowledge partitioning? This raises other questions: What types of knowledge domain partitioning currently exist and what are their limitations? How do these limitations affect conceptual modeling and to what extent do they prevent the implementation of more powerful search, retrieval and inference methods?

The rest of this paragraph is organized as follows: In the Related Work, we discuss what approaches already exist for the partitioning of classes and what shortcomings they have. Basic naming conventions and formal definitions are then introduced in the Preliminaries. The Methodology introduces Partitioning Classes (PC) using examples for attributes such as ‘gender’, ‘color’, ‘warm-blooded’, and ‘LifePhase’. As a special type of PCs the concept of Boolean PCs is also described. We also explain, how the properties of PCs, such as multiplicity und mutability are preserved. In the Evaluation, the question of whether it is possible to save storage space and to increase performance when processing conjunctive queries is examined. In the Results we use the Multi-Level Modeling (MLM) of other authors to compare how PCs can be used to streamline conceptual modeling. Under the heading of orthogonality, we also discuss how more flexibility and richness in modeling can be gained through the use of PCs. In the Results, we summarize the results.

Extension: deriver.app

PTCL mirror: subchapters in the sidebar; canonical overview on taoke.de — PTCL. Deriver documentation.

Source: taoke.de — PTCL Introduction.