Theories of skill acquisition have made radically different predictions about the role of general problem‐solving methods in acquiring rules that promote effective transfer to new problems. Under one view, methods that focus on reaching specific goals, such as means‐ends analysis, are assumed to provide the basis for efficient knowledge compilation (Anderson, 1987), whereas under an alternative view such methods are believed to disrupt rule induction (Sweller, 1988). We suggest that the role of general methods in learning varies with both the (...) specificity of the problem solver's goal and the systematicity of the strategies used for testing hypotheses about rules. In the absence of a specific goal people are more likely to use a rule‐induction learning strategy, whereas provision of a specific goal fosters use of difference reduction, which tends to be a non‐rule‐induction strategy. We performed two experiments to investigate the impact of goal specificity and systematicity of rule‐induction strategies in learning and transfer within a complex dynamic system. The results of Experiment 1 indicated that during free exploration of a problem space, greater learning occurred if participants adopted more systematic strategies for rule induction, and that participants come to favor such strategies. Experiment 2 revealed that participants who were provided with a specific goal performed well on the initial problem but were impaired on a transfer test using a similar problem with a different goal. Instruction on a systematic rule‐induction strategy facilitated solution for both the initial and transfer problems, but participants' use of this strategy declined if they had a specific goal. Our results support Sweller's (1988) proposal that general problemsolving methods applied to a specific goal foster acquisition of knowledge about an isolated solution path but do not provide an effective way of learning the overall structure of a problem space. We interpret these results in terms of dualspace theories of search through problem space. (shrink)

One of the most influential studies in all expertise research is de Groot’s (1946) study of chess players, which suggested that pattern recognition, rather than search, was the key determinant of expertise. Many changes have occurred in the chess world since de Groot’s study, leading some authors to argue that the cognitive mechanisms underlying expertise have also changed. We decided to replicate de Groot’s study to empirically test these claims and to examine whether the trends in the data have changed (...) over time. Six Grandmasters, five International Masters, six Experts, and five Class A players completed the think-aloud procedure for two chess positions. Findings indicate that Grandmasters and International Masters search more quickly than Experts and Class A players, and that both groups today search substantially faster than players in previous studies. The findings, however, support de Groot’s overall conclusions and are consistent with predictions made by pattern recognition models. (shrink)

Proponents of moral enhancement present this biotechnology as a viable solution to social and political problems. The projected imperative to enhance ourselves morally is a direct response to our p...

In the two-envelope problem, a reasoner is offered two envelopes, one containing exactly twice the money in the other. After observing the amount in one envelope, it can be traded for the unseen contents of the other. It appears that it should not matter whether the envelope is traded, but recent mathematical analyses have shown that gains could be made if trading was a probabilistic function of amount observed. As a problem with a purely probabilistic solution, it provides a potentially (...) interesting way to test people's consistency with probabilistic models. Three experiments did this by varying the size of both the observed and maximum amounts, and their possible distribution. The results showed that trading decisions were affected by where the observed amount in the opened envelope fell in the distribution, though its size did not always do so. This suggests that participants’ trade decisions could be affected by the perceived probabilities of different observed amounts, which is consistent with the pro.. (shrink)

Yannos Kourayos et Bryan Burns Exploration du sanctuaire archaïque à Mandra sur l'île de Despotiko p. 133-174 Cet article présente les premiers résultats d'une fouille conduite à Mandra sur l'île de Despotiko, île inhabitée à l'Ouest de Paros et d'Antiparos. Ce sont les trouvailles de surface qui conduisirent à la fouille du Bâtiment A, grande construction de cinq pièces parallèles, peut-être un hestiatorion. L'interprétation du site comme sanctuaire se trouve confirmée par la découverte de nombreux objets votifs. La majorité du (...) mobilier — fragments de sculpture, céramique importée, large éventail d'objets en métal et de petits objets — découvert jusqu'à présent date de l'époque archaïque. Des pièces architecturales, dont beaucoup furent remployées dans des constructions postérieures, attestent la présence de plusieurs autres bâtiments doriques, alors qu'un long mur de pierre enclôt une vaste étendue à l'Est du Bâtiment A. Le nom d'Apollon sur des tessons suggère que le sanctuaire était dédié au dieu, le caractère féminin de nombreux ex-voto et la présence de plusieurs Délia dans les Cyclades qu'Artémis y était aussi vénérée. (shrink)