Abduction in Logic Programming started in the late 80s, early 90s, in an attempt to extend logic programming into a framework suitable for a variety of problems in Artificial Intelligence and other areas of Computer Science. This paper aims to chart out the main developments of the field over the last ten years and to take a critical view of these developments from several perspectives: logical, epistemological, computational and suitability to application. The paper attempts to expose some of the challenges and prospects for the further development of the field.

In this paper we propose a theoretical framework of distributed representations and a methodology of representational analysis for the study of distributed cognitive tasksÑtasks that require the processing of information distributed across the internal mind and the external environment. The basic principle of distributed representations is that the representational system of a distributed cognitive task is a set of internal and external representations, which together represent the abstract structure of the task. The basic strategy of representational analysis is to decompose the representation of a hierarchical task into its component levels so that the representational properties at each level can be independently examined. The theoretical framework and the methodology are used to analyze the hierarchical structure of the Tower of Hanoi problem. Based on this analysis, four experiments are designed to examine the representational properties of the Tower of Hanoi. Finally, the nature of external representations is discussed.

In this article we present two sets of experiments designed to investigate the acquisition of scalar implicatures. Scalar implicatures arise in examples like Some profissors are famous where the speaker's use of some typically indicates that s/he had reasons not to use a more informative term, e.g. all. Someprofissors are famous therefore gives rise to the implicature that not all professors are famous. Recent studies on the development of pragmatics suggest that preschool children are often insensitive to such implicatures when they interpret scalar terms (Noveck 2001 for terms like might and some; Chierchia, Crain, Guasti, Gualmini and Meroni 2001 for or). This conclusion raises two important questions: a) are all scalar terms treated in the same way by young children?, and b) does the child's difficulty reflect a genuine inability to derive scalar implicatures or is it due to demands imposed by the experimental task on an otherwise pragmatically savvy child? Experiment 1 addresses the first question by testing a group of 30 5-year-olds and 30 adults (all native speakers of Greek) on three different scales, meriki/ oli (some/all), dio/ tris (two/three) and arxi<o / teliono (start/finish). In each case, subjects were presented with contexts which satisfy the truth conditions of the stronger (i.e. more informative) terms on each scale (i.e. all, three and finish) but were described using the weaker terms of the scales (i.e. some, two, start). We found that while adults overwhelmingly rejected these infelicitous descriptions, children almost never did so. Children also differed from adults in that thei rejection rate on the numerical scale was reliably higher than on the two other scales. In order to address question (b), we trained a group of 30 5-year-olds to detect in...

Abstract not found

The authors outline a theory of conditionals of the form If A then C and If A then possibly C. The 2 sorts of conditional have separate core meanings that refer to sets of possibilities. Knowledge, pragmatics, and semantics can modulate these meanings. Modulation can add information about temporal and other relations between antecedent and consequent. It can also prevent the construction of possibilities to yield 10 distinct sets of possibilities to which conditionals can refer. The mental representation of a conditional normally makes explicit only the possibilities in which its antecedent is true, yielding other possibilities implicitly. Reasoners tend to focus on the explicit possibilities. The theory predicts the major phenomena of understanding and reasoning with conditionals. You reason about conditional relations because much of your knowledge is conditional. If you get caught speeding, then you pay a fine. If you have an operation, then you need time to recuperate. If you have money in the bank, then you can cash a check. Conditional reasoning is a central part of thinking, yet people do not always reason correctly. The lawyer Jan Schlictmann in a celebrated trial (see Harr, 1995, pp. 361–362) elicited the following information from an expert witness about the source of a chemical pollutant trichloroethylene (TCE):

This article presents a formal theory of robot perception as a form of abduction. The theory pins down the process whereby low-level sensor data is transformed into a symbolic representation of the external world, drawing together aspects such as incompleteness, top-down information flow, active perception, attention, and sensor fusion in a unifying framework. In addition, a number of themes are identified that are common to both the engineer concerned with developing a rigorous theory of perception, such as the one on offer here, and the philosopher of mind who is exercised by questions relating to mental representation and intentionality.

this paper is to show that this misunderstanding of the nature of logic by these and other prominent programs of research into human reasoning, has led to an impoverishment of empirical investigation into what subjects are doing in the selection task and to a wholly unnecessary and damaging rift between logically based cognitive theories of natural language interpretation on the one hand, and psychological experimentation on reasoning on the other. We will show that when empirical exploration is based on an informed understanding of logically based cognitive theory, the evidence strongly suggests a nearly opposite evolutionary account of the relation between the emergence of human communication capacities and economic exchange, and that logical semantics already has accounts of context senstivity to o#er far in advance of mental models theory's new creations

The authors examined cultural preferences for formal versus intuitive reasoning among East Asian (Chinese and Korean), Asian American, and European American university students. We investigated categorization (Studies 1 and 2), conceptual structure (Study 3), and deductive reasoning (Studies 3 and 4). In each study a cognitive conflict was activated between formal and intuitive strategies of reasoning. European Americans, more than Chinese and Koreans, set aside intuition in favor of formal reasoning. Conversely, Chinese and Koreans relied on intuitive strategies more than European Americans. Asian Americans' reasoning was either identical to that of European Americans, or intermediate. Differences emerged against a background of similar reasoning tendencies across cultures in the absence of conflict between formal and intuitive strategies.

In this paper we present a systematic study of abductive consequence relations. We show that a monotone abductive consequence relation satisfies the properties of a cumulative monotonic system as defined by Kraus, Lehmann and Magidor when the disjunction of all abductive explanations is the explanation used to justify the observations. We also show that, in general, for this class of abductive consequence relations the Or rule does not hold. We present an example that shows that when there are preferences between different abductive explanations monotonicity does not hold. We show that non-monotonic abductive systems preserve a partial version of rational monotonicity and in fact are very similar to rational relations. We also present semantic characterizations of both monotonic and non-monotonic abductive systems in terms of cumulative models as defined by Kraus, Lehmann and Magidor. Keywords: Abduction, non-monotonic consequence relations, non-monotonic logic, belief revision. 1 I...

If a person doesn’t give something to me, I won’t give anything to that person. If I’m sitting eating, and someone like that comes by, I say, “Uhn, uhn. I’m not going to give any of this to you. When you have food, the things you do with it make me unhappy. If you even once in a while gave me something nice, I would surely give some of this to you.” Nisa from Nisa: The Life and Words of a!Kung Woman, Shostak, 1981, p. 89 Instead of keeping things, [!Kung] use them as gifts to express generosity and friendly intent, and to put people under obligation to make return tokens of friendship....In reciprocating, one does not give the same object back again but something of comparable value. Eland fat is a very highly valued gift...Toma said that when he had eland fat to give, he took shrewd note of certain objects he might like to have and gave their owners especially generous gifts of fat. Marshall, 1976, pp. 366–369