Ludger Jansen

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.

Tun und Können erläutert und diskutiert den Gründungstext der Modalontologie: das neunte Buch der Metaphysik des Aristoteles. Aristoteles' Thesen und Argumente werden zum ersten Mal in Gänze mit formalen analytischen Mitteln rekonstruiert und auf ihre Kohärenz und Gültigkeit geprüft. Erstmals verwendet der Autor dazu eine adverbiale Analyse von Ausdrücken des Könnens und des Vermögens als Prädikatmodifikatoren. Das Buch zeigt, dass Aristoteles' Theorie der Vermögen nicht nur eine konsistente, sondern auch eine leistungsfähige Analyse von Dispositionen und Dispositionsprädikaten bietet. Die Neuausgabe wurde vollständig durchgesehen und um weiterführende Anhänge ergänzt. Der Inhalt: Können, Tun und Möglichkeit. Eine Einführung • Die kausale Dimension von Vermögen • Die ontologische Dimension von Vermögen• Eine notwendige Bedingung für Vermögen • Hindernisse und Verwirklichung • Prioritätsfragen • Aristotle’s Theory of Dispositions • Das Problem des Neuen • Planners, Deciders, Performers

It is widespread practice to define artefacts as entities that owe their existence to plan-based acts of production that aim at a certain use of the produced thing. According to this definition, artefacts are essentially intention-dependent. For this reason, artefacts are threatened by marginalisation within standard naturalised ontologies. I discuss three families of marginalisation strategies: elimination, reduction and supervenience. I argue that all of these strategies fail, as they lead to false implications, with the possible exception of four-dimensional supervenience, which might well be true, but remains completely uninformative in respect to artefacts. The crucial issue in this regard is what Peter van Inwagen calls the Duplication Principle which is undermined by thought experiments involving chance entities or duplication. Hence, materialistic ontologies are not, as Peter van Inwagen wants us to believe, a Copernican revolution in ontology; they are simply not adequate for the domain of artefacts

Was ist der Mensch? Das ist eine der "großen" philosophischen Fragen, und immer wieder werden bei der Beantwortung dieser Frage antike Denker zitiert. Das vorliegende Buch ist die erste Gesamtdarstellung des anthropologischen Denkens in der Antike. In fünfzehn Beiträgen behandelt der Band alle wichtigen antiken Philosophen und Philosophenschulen, von den Vorsokratikern bis zu Augustinus. Bewusst schaut der Band dabei über die Grenzen dessen hinaus, was wir heute "Philosophie" nennen, und wendet sich auch Denkern aus den Gebieten der antiken Literatur, Theologie und Medizin zu. Der Band richtet sich an Philosophen und Altphilologen ebenso wie Historiker und Theologen. Die Beiträge eignen sich auch als Einführung in die jeweiligen Autoren und Schulen für Studierende und interessierte Leser aus anderen Disziplinen. Speziell für diesen Leserkreis liefern die Beiträge Hinweise für die weitere Lektüre. (publisher) Mit Beiträgen von Ursula Bittrich, Yves Bossart, Jan N. Bremmer, Thomas Buchheim, Christoph Horn, Ludger Jansen, Christoph Jedan, Geurt Henk van Kooten, Zbigniew Nerczuk, Matthias Perkams, Joachim Söder, Niko Strobach, Hartmut Westermann und Jula Wildberger

The construction of complex ontologies can be facilitated by adapting existing vocabularies. There is little clarity and in fact little consensus as to what modifications of vocabularies are necessary in order to re-engineer them into ontologies. In this paper we present a method that provides clear steps to follow when re-engineering a thesaurus. The method makes use of top-level ontologies and was derived from the structural differences between thesauri and ontologies as well as from best practices in modeling, some of which have been advocated in the biomedical domain. We illustrate each step of our method with examples from a re-engineering case study about agricultural fertilizers based on the AGROVOC thesaurus. Our method makes clear that re-engineering thesauri requires far more than just a syntactic conversion into a formal language or other easily automatable steps. The method can not only be used for re-engineering thesauri, but does also summarize steps for building ontologies in general, and can hence be adapted for the re-engineering of other types of vocabularies or terminologies.

BACKGROUND Understanding, modelling and influencing the transition between different states of cells, be it reprogramming of somatic cells to pluripotency or trans-differentiation between cells, is a hot topic in current biomedical and cell-biological research. Nevertheless, the large body of published knowledge in this area is underused, as most results are only represented in natural language, impeding their finding, comparison, aggregation, and usage. Scientific understanding of the complex molecular mechanisms underlying cell transitions could be improved by making essential pieces of knowledge available in a formal (and thus computable) manner. RESULTS We describe the outline of two ontologies for cell phenotypes and for cellular mechanisms which together enable the representation of data curated from the literature or obtained by bioinformatics analyses and thus for building a knowledge base on mechanisms involved in cellular reprogramming. In particular, we discuss how comprehensive ontologies of cell phenotypes and of changes in mechanisms can be designed using the entity-quality (EQ) model. CONCLUSIONS We show that the principles for building cellular ontologies published in this work allow deeper insights into the relations between the continuants (cell phenotypes) and the occurrents (cell mechanism changes) involved in cellular reprogramming, although implementation remains for future work. Further, our design principles lead to ontologies that allow the meaningful application of similarity searches in the spaces of cell phenotypes and of mechanisms, and, especially, of changes of mechanisms during cellular transitions.