In the current literature of knowledge management and artificial intelligence, several different approaches to the problem have been carried out of developing domain ontologies from scratch. All these approaches deal fundamentally with three problems: (1) providing a collection of general terms describing classes and relations to be employed in the description of the domain itself; (2) organizing the terms into a taxonomy of the classes by the ISA relation; and (3) expressing in an explicit way the constraints that make the ISA pairs meaningful. Though a number of such approaches can be found, no systematic analysis of them exists which can be used to understand the inspiring motivation, the applicability context, and the structure of the approaches. In this paper, we provide a framework for analyzing the existing methodologies that compares them to a set of general criteria. In particular, we obtain a classification based upon the direction of ontology construction; bottom-up are those methodologies that start with some descriptions of the domain and obtain a classification, while top-down ones start with an abstract view of the domain itself, which is given a priori. The resulting classification is useful not only for theoretical purposes but also in the practice of deployment of ontologies in Information Systems, since it provides a framework for choosing the right methodology to be applied in the specific context, depending also on the needs of the application itself.

The paper proposes a fresh look at the concept of goal and advances that motivational attitudes like desire, goal and intention are just facets of the broader notion of (acceptable) outcome. We propose to encode the preferences of an agent as sequences of "alternative acceptable outcomes". We then study how the agent's beliefs and norms can be used to filter the mental attitudes out of the sequences of alternative acceptable outcomes. Finally, we formalise such intuitions in a novel Modal Defeasible Logic and we prove that the resulting formalisation is computationally feasible.

Abstract. We propose algorithms to synthesise the specifications modelling the capabilities of an agent, the environment she acts in, and the governing norms, into a process graph. This process graph corresponds to a collection of courses of action and represents all the licit alternatives the agent may choose to meet her outcomes. The starting point is a compliant situation, i.e., a situation where an agent is capable of reaching all her outcomes without violating the norms. In this case, the resulting process will be compliant by design.

In the current literature of knowledge management and artificial intelligence, several different approaches to the problem have been carried out of developing domain ontologies from scratch. All these approaches deal fundamentally with three problems: (1) providing a collection of general terms describing classes and relations to be employed in the description of the domain itself; (2) organizing the terms into a taxonomy of the classes by the ISA relation; and (3) expressing in an explicit way the constraints that make the ISA pairs meaningful. Though a number of such approaches can be found, no systematic analysis of them exists which can be used to understand the inspiring motivation, the applicability context, and the structure of the approaches. In this paper, we provide a framework for analyzing the existing methodologies that compares them to a set of general criteria. In particular, we obtain a classification based upon the direction of ontology construction; bottom-up are those methodologies that start with some descriptions of the domain and obtain a classification, while top-down ones start with an abstract view of the domain itself, which is given a priori. The resulting classification is useful not only for theoretical purposes but also in the practice of deployment of ontologies in Information Systems, since it provides a framework for choosing the right methodology to be applied in the specific context, depending also on the needs of the application itself.

No abstract

We address the problem of define a modal defeasible theory able to capture intuitions as "being compliant" with a set of norms and a set of goals. We will treat norms and goals as modalised literals. From the definition of this new kind of logic, two main issues arises whether a theory is compliant or not: (a) how to revise a non compliant theory to obtain a new compliant one; (b) in case the theory is compliant how to create an entirely new process starting from the theory, i.e., from the fully declarative description of the specifications for a process and the norms. M. Palmirani et al (eds)

In the recent literature of Arti cial Intelligence, an intensive research e ort has been spent, for various algebras of qualitative relations used in the representation of temporal and spatial knowledge, on the problem of classifying the computational complexity of reasoning problems for subsets of algebras. The main purpose of these researches is to describe a restricted set of maximal tractable subalgebras, ideally in an exhaustive fashion with respect to the hosting algebras.In this paper we i n troduce a novel algebra for reasoning about Spatial Congruence, show that the satis ability problem in the spatial algebra MC-4 is NP-complete, and present a complete classi cation of tractability in the algebra, based on the individuation of three maximal tractable subclasses, one containing the basic relations. The three algebras are formed by 14, 10 and 9 relations out of 16 which form the full algebra.

We propose a systematic investigation on how to modify a preference relation in a defeasible logic theory to change the conclusions of the theory itself. We argue that the approach we adopt is applicable to legal reasoning, where users, in general, cannot change facts and rules, but can propose their preferences about the relative strength of the rules. We provide a comprehensive study of the possible combinatorial cases and we identify and analyse the cases where the revision process is successful. IntroductionTypically skeptical non-monotonic formalisms are equipped with techniques to address conflicts, where a conflict is a combination of reasoning chains leading to a contradiction. The most common device to handle conflicts is a preference or superiority relation over the elements used by the formalism to reason. These elements can be formulae, axioms, rules or arguments, and the preference relation states that one of such elements is to be preferred to another one when both can be used.In this research we concentrate on a specific rule-based non-monotonic formalism, Defeasible Logic, but the motivation behind the particular technical development applies in general to other rule-based formalisms. In a rule based formalism, typically knowledge is described in facts (describing immutable propositions/statements about a case), rules (describing relationships between a set of premises and a conclusion), and preference relation or superiority relation (describing the relative strength of rules). A revision operation transforms a theory by changing some of its elements, that is: facts, rules and superiority relation. Revision based on change of facts corresponds to an update operation [1], revision based on modification of rules has been investigated in [2], to the best of our knowledge, revision of non-monotonic theories based on modifications of the underlying superiority relation has been neglected so far. In this paper we concentrate on this issue, and we argue that, while little attention has been dedicated to this topic, it has natural correspondences to reasoning patterns in legal reasoning.The paper is organised as follows: In Section 2 we motivate that reasoning over preferences on rules and on how to modify the preferences is a natural reasoning pattern in legal reasoning. Then in Section 3 we introduce Defeasible Logic, the formalism chosen for our investigation; in particular we introduce new auxiliary proof tags to describe derivations in Defeasible logic. The new proof tags do not modify the expressive power of the logic, but they identify patterns where instances of the superiority relation contribute to the derivation of a conclusion. Armed with this technical machinery,