A multilevel study of leadership, empowerment, and performance in teams

A multilevel model of leadership, empowerment, and performance was tested using a sample of 62 teams, 445 individual members, 62 team leaders, and 31 external managers from 31 stores of a Fortune 500 company. Leader-member exchange and leadership climate related differently to individual and team empowerment and interacted to influence individual empowerment. Also, several relationships were supported in more but not in less interdependent teams. Specifically, leader-member exchange related to individual performance partially through individual empowerment; leadership climate related to team performance partially through team empowerment; team empowerment moderated the relationship between individual empowerment and performance; and individual performance was positively related to team performance. Contributions to team leadership theory, research, and practices are discussed.     

Complete Extensions in Argumentation Coincide with 3-Valued Stable Models in Logic Programming

In this paper, we prove the correspondence between complete extensions in abstract argumentation and 3-valued stable models in logic programming. This result is in line with earlier work of [6] that identified the correspondence between the grounded extension in abstract argumentation and the well-founded model in logic programming, as well as between the stable extensions in abstract argumentation and the stable models in logic programming.     

Meta-Argumentation Modelling I: Methodology and Techniques

In this paper, we introduce the methodology and techniques of meta-argumentation to model argumentation. The methodology of meta-argumentation instantiates Dung’s abstract argumentation theory with an extended argumentation theory, and is thus based on a combination of the methodology of instantiating abstract arguments, and the methodology of extending Dung’s basic argumentation frameworks with other relations among abstract arguments. The technique of meta-argumentation applies Dung’s theory of abstract argumentation to itself, by instantiating Dung’s abstract arguments with meta-arguments using a technique called flattening. We characterize the domain of instantiation using a representation technique based on soundness and completeness. Finally, we distinguish among various instantiations using the technique of specification languages.     

Modal Logics of Reactive Frames

A reactive graph generalizes the concept of a graph by making it dynamic, in the sense that the arrows coming out from a point depend on how we got there. This idea was first applied to Kripke semantics of modal logic in [2]. In this paper we strengthen that unimodal language by adding a second operator. One operator corresponds to the dynamics relation and the other one relates paths with the same endpoint. We explore the expressivity of this interpretation by axiomatizing some natural subclasses of reactive frames. The main objective of this paper is to present a methodology to study reactive logics using the existent classic techniques.     

Logical Modes of Attack in Argumentation Networks

This paper studies methodologically robust options for giving logical contents to nodes in abstract argumentation networks. It defines a variety of notions of attack in terms of the logical contents of the nodes in a network. General properties of logics are refined both in the object level and in the metalevel to suit the needs of the application. The network-based system improves upon some of the attempts in the literature to define attacks in terms of defeasible proofs, the so-called rule-based systems. We also provide a number of examples and consider a rigorous case study, which indicate that our system does not suffer from anomalies. We define consequence relations based on a notion of defeat, consider rationality postulates, and prove that one such consequence relation is consistent.     

Annotation Theories over Finite Graphs

In the current paper we consider theories with vocabulary containing a number of binary and unary relation symbols. Binary relation symbols represent labeled edges of a graph and unary relations represent unique annotations of the graph’s nodes. Such theories, which we call annotation theories, can be used in many applications, including the formalization of argumentation, approximate reasoning, semantics of logic programs, graph coloring, etc. We address a number of problems related to annotation theories over finite models, including satisfiability, querying problem, specification of preferred models and model checking problem. We show that most of considered problems are NPTime- or co-NPTime-complete. In order to reduce the complexity for particular theories, we use second-order quantifier elimination. To our best knowledge none of existing methods works in the case of annotation theories. We then provide a new second-order quantifier elimination method for stratified theories, which is successful in the considered cases. The new result subsumes many other results, including those of [2, 28, 21].     

Analysis of the Talmudic Argumentum A Fortiori Inference Rule (Kal Vachomer) using Matrix Abduction

We motivate and introduce a new method of abduction, Matrix Abduction, and apply it to modelling the use of non-deductive inferences in the Talmud such as Analogy and the rule of Argumentum A Fortiori. Given a matrix \({\mathbb {A}}\) with entries in {0, 1}, we allow for one or more blank squares in the matrix, say a _i,j =?. The method allows us to decide whether to declare a _i,j = 0 or a _i,j = 1 or a _i,j =? undecided. This algorithmic method is then applied to modelling several legal and practical reasoning situations including the Talmudic rule of Kal-Vachomer. We add an Appendix showing that this new rule of Matrix Abduction, arising from the Talmud, can also be applied to the analysis of paradoxes in voting and judgement aggregation. In fact we have here a general method for executing non-deductive inferences.     

MIGHT KANTIAN CONTRACTUALISM BE THE SUPREME PRINCIPLE OF MORALITY?

According to Parfit, the best version of Kantian ethics takes as its central principle Kantian Contractualism: the thesis that everyone ought to follow the principles whose universal acceptance everyone could rationally will. This paper examines that thesis, identifies a class of annoying counterexamples, and suggests that when Kantian Contractualism is modified in response to these examples, the resulting principle is too complex and ad hoc to serve as the 'supreme principle of morality'.     

The Effectiveness of Family History Questionnaires in Cancer Genetic Counseling

The number of individuals receiving genetic counseling for hereditary breast and ovarian cancer syndrome has steadily risen. To triage patients for genetic counseling and to help reduce the amount of time needed by a genetic counselor in direct patient contact, many clinics have implemented the use of family history questionnaires. Although such questionnaires are widely used, scant literature exists evaluating their effectiveness. This article explores the extent to which family history questionnaires are being used in Ontario and addresses the utility of such questionnaires in one familial cancer clinic. By comparing the pedigrees created from questionnaires to those updated during genetic counseling, the accuracy and effectiveness of the questionnaires was explored. Of 121 families recruited into the study, 12% acquired changes to their pedigree that led to a revised probability estimate for having a BRCA1 or BRCA2 mutation and 5% acquired changes that altered their eligibility for genetic testing. No statistically significant difference existed between the eligibility for genetic testing prior to and post counseling. This suggests that family history questionnaires can be effective at obtaining a family history and accurately assessing eligibility for genetic testing. Based on the variables that were significantly associated with a change in probability estimate, we further present recommendations for improving the clarity of such questionnaires and therefore the ease of use by patients.