We consider a special case of heuristics, namely numeric heuristic evaluation functions, and their use in artificial intelligence search algorithms. The problems they are applied to fall into three general classes: single-agent path-finding problems, two-player games, and constraint-satisfaction problems. In a single-agent path-finding problem, such as the Fifteen Puzzle or the travelling salesman problem, a single agent searches for a shortest path from an initial state to a goal state. Two-player games, such as chess and checkers, involve an adversarial relationship (...) between two players, each trying to win the game. In a constraint-satisfaction, problem, such as the 8-Queens problem, the task is to find a state that satisfies a set of constraints. All of these problems are computationally intensive, and heuristic evaluation functions are used to reduce the amount of computation required to solve them. In each case we explain the nature of the evaluation functions used, how they are used in search algorithms, and how they can be automatically learned or acquired. (shrink)

Reviews evidence which suggests that there may be little or no direct introspective access to higher order cognitive processes. Ss are sometimes unaware of the existence of a stimulus that importantly influenced a response, unaware of the existence of the response, and unaware that the stimulus has affected the response. It is proposed that when people attempt to report on their cognitive processes, that is, on the processes mediating the effects of a stimulus on a response, they do not do (...) so on the basis of any true introspection. Instead, their reports are based on a priori, implicit causal theories, or judgments about the extent to which a particular stimulus is a plausible cause of a given response. This suggests that though people may not be able to observe directly their cognitive processes, they will sometimes be able to report accurately about them. Accurate reports will occur when influential stimuli are salient and are plausible causes of the responses they produce, and will not occur when stimuli are not salient or are not plausible causes. (shrink)

The authors find East Asians to be holistic, attending to the entire field and assigning causality to it, making relatively little use of categories and formal logic, and relying on "dialectical" reasoning, whereas Westerners, are more analytic, paying attention primarily to the object and the categories to which it belongs and using rules, including formal logic, to understand its behavior. The 2 types of cognitive processes are embedded in different naive metaphysical systems and tacit epistemologies. The authors speculate that the (...) origin of these differences is traceable to markedly different social systems. The theory and the evidence presented call into question long-held assumptions about basic cognitive processes and even about the appropriateness of the process–content distinction. (shrink)

Staged 2 different videotaped interviews with the same individual—a college instructor who spoke English with a European accent. In one of the interviews the instructor was warm and friendly, in the other, cold and distant. 118 undergraduates were asked to evaluate the instructor. Ss who saw the warm instructor rated his appearance, mannerisms, and accent as appealing, whereas those who saw the cold instructor rated these attributes as irritating. Results indicate that global evaluations of a person can induce altered evaluations (...) of the person's attributes, even when there is sufficient information to allow for independent assessments of them. Furthermore, Ss were unaware of this influence of global evaluations on ratings of attributes. In fact, Ss who saw the cold instructor actually believed that the direction of influence was opposite to the true direction. They reported that their dislike of the instructor had no effect on their rating of his attributes but that their dislike of his attributes had lowered their global evaluations of him. (shrink)

This classic, first published in 1969, introduces to English-speaking readers a field which is of increasing importance in contemporary philosophy and theology--hermeneutics, the theory of understanding, or interpretation. Richard E. Palmer, utilizing largely untranslated sources, treats principally of the conception of hermeneutics enunciated by Heidegger and developed into a "philosophical hermeneutics" by Hans-Georg Gadamer. He provides a brief overview of the field by surveying some half-dozen alternate definitions of the term and by examining in detail the contributions of Friedrich (...) Schleiermacher and Wilhelm Dilthey. In the Manifesto which concludes the book, Palmer suggests the potential significance of hermeneutics for literary interpretation. (shrink)

A long-standing challenge to evolutionary theory has been whether it can explain the origin of complex organismal features. We examined this issue using digital organisms—computer programs that self-replicate, mutate, compete and evolve. Populations of digital organisms often evolved the ability to perform complex logic functions requiring the coordinated execution of many genomic instructions. Complex functions evolved by building on simpler functions that had evolved earlier, provided that these were also selectively favoured. However, no particular intermediate stage was essential for evolving (...) complex functions. The first genotypes able to perform complex functions differed from their non-performing parents by only one or two mutations, but differed from the ancestor by many mutations that were also crucial to the new functions. In some cases, mutations that were deleterious when they appeared served as stepping-stones in the evolution of complex features. These findings show how complex functions can originate by random mutation and natural selection. (shrink)

This book examines two questions: Do people make use of abstract rules such as logical and statistical rules when making inferences in everyday life? Can such abstract rules be changed by training? Contrary to the spirit of reductionist theories from behaviorism to connectionism, there is ample evidence that people do make use of abstract rules of inference -- including rules of logic, statistics, causal deduction, and cost-benefit analysis. Such rules, moreover, are easily alterable by instruction as it occurs in classrooms (...) and in brief laboratory training sessions. The fact that purely formal training can alter them and that those taught in one content domain can "escape" to a quite different domain for which they are also highly applicable shows that the rules are highly abstract. The major implication for cognitive science is that people are capable of operating with abstract rules even for concrete, mundane tasks; therefore, any realistic model of human inferential capacity must reflect this fact. The major implication for education is that people can be far more broadly influenced by training than is generally supposed. At high levels of formality and abstraction, relatively brief training can alter the nature of problem-solving for an infinite number of content domains. (shrink)

H.P. Grice is known principally for his influential contributions to the philosophy of language, but his work also includes treatises on the philosophy of mind, ethics, and metaphysics--much of which is unpublished to date. This collection of original essays by such philosophers as Nancy Cartwright, Donald Davidson, Gilbert Harman, and P.F. Strawson demonstrates the unified and powerful character of Grice's thoughts on being, mind, meaning, and morals. An introductory essay by the editors provides the first overview of Grice's work.

The fitness of any evolutionary unit can be understood in terms of its two basic components: fecundity (reproduction) and viability (survival). Trade-offs between these fitness components drive the evolution of life-history traits in extant multicellular organisms. We argue that these trade-offs gain special significance during the transition from unicellular to multicellular life. In particular, the evolution of germ–soma specialization and the emergence of individuality at the cell group (or organism) level are also consequences of trade-offs between the two basic fitness (...) components, or so we argue using a multilevel selection approach. During the origin of multicellularity, we study how the group trade-offs between viability and fecundity are initially determined by the cell level trade-offs, but as the transition proceeds, the fitness trade-offs at the group level depart from those at the cell level. We predict that these trade-offs begin with concave curvature in single-celled organisms but become increasingly convex as group size increases in multicellular organisms. We argue that the increasingly convex curvature of the trade-off function is driven by the cost of reproduction which increases as group size increases. We consider aspects of the biology of the volvocine green algae – which contain both unicellular and multicellular members – to illustrate the principles and conclusions discussed. (shrink)

128 female Ss were asked to make 4 judgments about a young woman after reading her "job application portfolio." Five characteristics of the young woman were manipulated orthogonally. Ss were asked to report how each of the 5 manipulated factors had influenced each of their judgments. "Observer Ss," who had access only to very impoverished descriptions of each of the 5 factors, were asked to predict how each of the factors would influence each of the judgments. Results show that S (...) reports about the effects of the factors on the judgments were in general highly inaccurate; observer predictions were extremely similar to S reports; for the single judgment for which Ss showed substantial accuracy, observer predictions were as accurate as S reports. Results indicate that whatever introspective access to cognitive processes may exist, it is not sufficient to produce generally accurate reports about such processes, nor even to produce reports that differ much from those of poorly informed outside observers. (shrink)