Ludger Jansen

Ontological realism is a philosophical stance that provides a definitional framework for ontologies and is referred to by various applied ontologists. From a computer science perspective, ontologies are often associated with formal languages for the representation of ontologies like the Web Ontology Language (OWL). It has, however, not been made explicit how the realist framework is related to the representation formalism. We analyse how the representational units of OWL can be used for modelling realist ontologies. While OWL is sufficiently close to the realist framework of ontologies to describe them, there are categories in OWL that are alien to realist ontologies or duplicate categories in realist ontologies. This clarification allows separating talk about ontologies in general from talk about their specific representation.

Taking Thomas Aquinas's interpretation of the prologue of St John's gospel (in his Lectura super loannem Evangelium) as example, I first discuss eight differences between medieval biblical interpretation and modern exegesis, especially Aquinas's frequent use of philosophical opinions in interpreting the Bible, taken mostly from Aristotle. Second, I account for these differences by reconstructing Aquinas's hermeneutics, hinging, as is shown, upon the assumption that scripture was authored by God infallible and, therefore, only contains true statements. From this starting point Aquinas is lead to a holistic hermeneutics: The interpretation of a biblical statement can be judged on only within the context of an entire theory of God, the world, and of the interpretation of the other biblical statements. Thirdly, this view is discussed systematically and critically.

Background Ontology Design Patterns (ODPs) are representational artifacts devised to offer solutions for recurring ontology design problems. They promise to enhance the ontology building process in terms of flexibility, re-usability and expansion, and to make the result of ontology engineering more predictable. In this paper, we analyze ODP repositories and investigate their relation with upper-level ontologies. In particular, we compare the BioTop upper ontology to the Action ODP from the NeOn an ODP repository. In view of the differences in the respective approaches, we investigate whether the Action ODP can be embedded into BioTop. We demonstrate that this requires re-interpreting the meaning of classes of the NeOn Action ODP in the light of the precepts of realist ontologies. Results As a result, the re-design required clarifying the ontological commitment of the ODP classes by assigning them to top-level categories. Thus, ambiguous definitions are avoided. Classes of real entities are clearly distinguished from classes of information artifacts. The proposed approach avoids the commitment to the existence of unclear future entities which underlies the NeOn Action ODP. Our re-design is parsimonious in the sense that existing BioTop content proved to be largely sufficient to define the different types of actions and plans. Conclusions The proposed model demonstrates that an expressive upper-level ontology provides enough resources and expressivity to represent even complex ODPs, here shown with the different flavors of Action as proposed in the NeOn ODP. The advantage of ODP inclusion into a top-level ontology is the given predetermined dependency of each class, an existing backbone structure and well-defined relations. Our comparison shows that the use of some ODPs is more likely to cause problems for ontology developers, rather than to guide them. Besides the structural properties, the explanation of classification results were particularly hard to grasp for 'self-sufficient' ODPs as compared with implemented and 'embedded' upper-level structures which, for example in the case of BioTop, offer a detailed description of classes and relations in an axiomatic network. This ensures unambiguous interpretation and provides more concise constraints to leverage on in the ontology engineering process.

Like the doctrine of the categories in general, Aristotle’s category of the relative fulfils disparate functions: On the one hand, the category of the pros ti fulfils a dialectic or logical function that aims at the avoidance of fallacies. On the other hand, the category respects the peculiar mode of being of the relative. Taking these two different functions into consideration helps with the interpretation of Aristotle’s two definitions of the relative and his treatment of the properties of the relative in Cat. 7, with the question whether corresponding relatives are of equal priority or ontologically independent, with the genus-species problem, and with the categorical classification of potency and act.

This paper questions the widespread supposition that artifact kinds are kinds of artifacts. I will argue that this supposition rests on a one-sided diet of examples taken from inanimate physical things and the neglect of social and biological artifacts. I will argue that belonging to an artifact kind and being an artifact are independent Features: The first divides off artifacts from non-artifacts, the second rests on the distinction between instances of artifacts kinds and instances of natural kinds. I claim that these two distinctions are orthogonal to each other, and besides the two canonical combinations of artificial instances of artifact kinds and non-artificial instances of natural kinds there are also non-artificial instances of artifact kinds and artificial instances of natural kinds. Moreover, as some artificial living beings are self-reproducing, some instances of an artifact kind are not themselves artifacts. Hence artifact kinds are not of necessity kinds of artifacts.

BACKGROUND The importance of ontologies in the biomedical domain is generally recognized. However, their quality is often too poor for large-scale use in critical applications, at least partially due to insufficient training of ontology developers. OBJECTIVE To show the efficacy of guideline-based ontology development training on the performance of ontology developers. The hypothesis was that students who received training on top-level ontologies and design patterns perform better than those who only received training in the basic principles of formal ontology engineering. METHODS A curriculum was implemented based on a guideline for ontology design. A randomized controlled trial on the efficacy of this curriculum was performed with 24 students from bioinformatics and related fields. After joint training on the fundamentals of ontology development the students were randomly allocated to two groups. During the intervention, each group received training on different topics in ontology development. In the assessment phase, all students were asked to solve modeling problems on topics taught differentially in the intervention phase. Primary outcome was the similarity of the students’ ontology artefacts compared with gold standard ontologies developed by the authors before the experiment; secondary outcome was the intra-group similarity of group members’ ontologies. RESULTS The experiment showed no significant effect of the guideline-based training on the performance of ontology developers (a) the ontologies developed after specific training were only slightly but not significantly closer to the gold standard ontologies than the ontologies developed without prior specific training; (b) although significant differences for certain ontologies were detected, the intra-group similarity was not consistently influenced in one direction by the differential training. CONCLUSION Methodologically limited, this study cannot be interpreted as a general failure of a guideline-based approach to ontology development. Further research is needed to increase insight into whether specific development guidelines and practices in ontology design are effective.

In order to develop the ontology of tendencies for use in the representation of medical knowledge, tendencies are compared with other kinds of entities possessing the realizable-realization structure, specifically: dispositions, propensities, abilities and virtues. The peculiarities of tendencies are discussed and a standard schema of tendency ascription is developed in order to represent the relations between the ascriptions of tendency tokens to particulars and the ascriptions of tendency types to universals. Two nonstandard cases and their epistemic variants are discussed.

Dispositions and tendencies feature significantly in the biomedical domain and therefore in representations of knowledge of that domain. They are not only important for specific applications like an infectious disease ontology, but also as part of a general strategy for modelling knowledge about molecular interactions. But the task of representing dispositions in some formal ontological systems is fraught with several problems, which are partly due to the fact that Description Logics can only deal well with binary relations. The paper will discuss some of the results of the philosophical debate about dispositions, in order to see whether the formal relations needed to represent dispositions can be broken down to binary relations. Finally, we will discuss problems arising from the possibility of the absence of realizations, of multi-track or multi-trigger dispositions and offer suggestions on how to deal with them.

Objectives: Medical decision support and other intelligent applications in the life sciences depend on increasing amounts of digital information. Knowledge bases as well as formal ontologies are being used to organize biomedical knowledge and data. However, these two kinds of artefacts are not always clearly distinguished. Whereas the popular RDF(S) standard provides an intuitive triple-based representation, it is semantically weak. Description logics based ontology languages like OWL-DL carry a clear-cut semantics, but they are computationally expensive, and they are often misinterpreted to encode all kinds of statements, including those which are not ontological. Method: We distinguish four kinds of statements needed to comprehensively represent domain knowledge: universal statements, terminological statements, statements about particulars and contingent statements. We argue that the task of formal ontologies is solely to represent universal statements, while the non-ontological kinds of statements can nevertheless be connected with ontological representations. To illustrate these four types of representations, we use a running example from parasitology. Results: We finally formulate recommendations for semantically adequate ontologies that can efficiently be used as a stable framework for more context-dependent biomedical knowledge representation and reasoning applications like clinical decision support systems.

There are group-actions, and if actions are intentional, there should also be group-intentions. Who has got these intentions? The groups? This seems to be the natural answer. But then: Groups do not have a mind or brain of there own to form any mental attitude. Different kinds of individualistic analyses of group-intentions have been suggested in the literature. On the one hand there are suggestions to reduce group intentions to a complex of different Iattitudes. John Searle, on the other hand, suggests a special social kind of attitudes, namely we-intentions. We-intentions are being had by individual persons, though they have the form “We intend to do such-and-such”. However, because of the fallibility of Searlian we-intentions and the possibility of ignorance this concept is of no help: We-intentions are neither necessary nor sufficient for group-intentions. In this respect, Margaret Gilbert’s approach is much more successful, though it covers only a special case, namely small-scale informal groups. I suggest a generalised solution in order to cover also large-scale and formal groups.