9,077 research outputs found

    The role of constraints in expert memory

    Get PDF
    A great deal of research has been devoted to developing process models of expert memory. However, K. J. Vicente and J. H. Wang (1998) proposed (a) that process theories do not provide an adequate account of expert recall in domains in which memory recall is a contrived task and (b) that a product theory, the constraint attunement hypothesis (CAH), has received a significant amount of empirical support. We compared 1 process theory (the template theory; TT; F. Gobet & H. A. Simon, 1996c) with the CAH in chess. Chess players (N = 36) differing widely in skill levels were required to recall briefly presented chess positions that were randomized in various ways. Consistent with TT, but inconsistent with the CAH, there was a significant skill effect in a condition in which both the location and distribution of the pieces were randomized. These and other results suggest that process models such as TT can provide a viable account of expert memory in chess

    Templates in chess memory: A mechanism for recalling several boards

    Get PDF
    This paper addresses empirically and theoretically a question derived from the chunking theory of memory (Chase & Simon, 1973): To what extent is skilled chess memory limited by the size of short-term memory (about 7 chunks)? This question is addressed first with an experiment where subjects, ranking from class A players to grandmasters, are asked to recall up to 5 positions presented during 5 seconds each. Results show a decline of percentage of recall with additional boards, but also show that expert players recall more pieces than is predicted by the chunking theory in its original form. A second experiment shows that longer latencies between the presentation of boards facilitate recall. In a third experiment, a Chessmaster gradually increases the number of boards he can reproduce with higher than 70% average accuracy to nine, replacing as many as 160 pieces correctly. To account for the results of these experiments, a revision of the Chase-Simon theory is proposed. It is suggested that chess players, like experts in other recall tasks, use long-term memory retrieval structures (Chase & Ericsson, 1982) or templates in addition to chunks in STM, to store information rapidly

    Identifying the Associations between Child Temperament and Father Involvement: Theoretical Considerations and Empirical Evidence

    Get PDF
    Using a sample of resident fathers (either married or cohabiting) from the Fragile Families and Child Wellbeing Study (N = 2,213), this study assessed the relationship between child temperament and father involvement. The direct effects of child temperament on father involvement, as well as its moderating effect on the association between other predictor variables and father involvement were measured. A two-equation model was estimated, using a two-stage least squares (2SLS) regression procedure. Findings suggest that fathers are less involved with temperamentally difficult children than with temperamentally easy children. Further, temperament moderated the strength of the association between parental relationship quality and father involvement for married fathers. Implications for intervention programs targeted at increasing paternal involvement are discussed.Father Involvement, Child Temperament, Parental Relationship Quality, Moderation Effects, Endogeneity-Exogeneity, 2SLS

    CHESS (CgHExpreSS): A comprehensive analysis tool for the analysis of genomic alterations and their effects on the expression profile of the genome

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Genomic alterations frequently occur in many cancer patients and play important mechanistic roles in the pathogenesis of cancer. Furthermore, they can modify the expression level of genes due to altered copy number in the corresponding region of the chromosome. An accumulating body of evidence supports the possibility that strong genome-wide correlation exists between DNA content and gene expression. Therefore, more comprehensive analysis is needed to quantify the relationship between genomic alteration and gene expression. A well-designed bioinformatics tool is essential to perform this kind of integrative analysis. A few programs have already been introduced for integrative analysis. However, there are many limitations in their performance of comprehensive integrated analysis using published software because of limitations in implemented algorithms and visualization modules.</p> <p>Results</p> <p>To address this issue, we have implemented the Java-based program CHESS to allow integrative analysis of two experimental data sets: genomic alteration and genome-wide expression profile. CHESS is composed of a genomic alteration analysis module and an integrative analysis module. The genomic alteration analysis module detects genomic alteration by applying a threshold based method or SW-ARRAY algorithm and investigates whether the detected alteration is phenotype specific or not. On the other hand, the integrative analysis module measures the genomic alteration's influence on gene expression. It is divided into two separate parts. The first part calculates overall correlation between comparative genomic hybridization ratio and gene expression level by applying following three statistical methods: simple linear regression, Spearman rank correlation and Pearson's correlation. In the second part, CHESS detects the genes that are differentially expressed according to the genomic alteration pattern with three alternative statistical approaches: Student's t-test, Fisher's exact test and Chi square test. By successive operations of two modules, users can clarify how gene expression levels are affected by the phenotype specific genomic alterations. As CHESS was developed in both Java application and web environments, it can be run on a web browser or a local machine. It also supports all experimental platforms if a properly formatted text file is provided to include the chromosomal position of probes and their gene identifiers.</p> <p>Conclusions</p> <p>CHESS is a user-friendly tool for investigating disease specific genomic alterations and quantitative relationships between those genomic alterations and genome-wide gene expression profiling.</p

    EU accession and Poland's external trade policy

    Get PDF
    No description supplie

    Innate talents: reality or myth?

    Get PDF
    Talents that selectively facilitate the acquisition of high levels of skill are said to be present in some children but not others. The evidence for this includes biological correlates of specific abilities, certain rare abilities in autistic savants, and the seemingly spontaneous emergence of exceptional abilities in young children, but there is also contrary evidence indicating an absence of early precursors of high skill levels. An analysis of positive and negative evidence and arguments suggests that differences in early experiences, preferences, opportunities, habits, training, and practice are the real determinants of excellence

    A Survey of Monte Carlo Tree Search Methods

    Get PDF
    Monte Carlo tree search (MCTS) is a recently proposed search method that combines the precision of tree search with the generality of random sampling. It has received considerable interest due to its spectacular success in the difficult problem of computer Go, but has also proved beneficial in a range of other domains. This paper is a survey of the literature to date, intended to provide a snapshot of the state of the art after the first five years of MCTS research. We outline the core algorithm's derivation, impart some structure on the many variations and enhancements that have been proposed, and summarize the results from the key game and nongame domains to which MCTS methods have been applied. A number of open research questions indicate that the field is ripe for future work

    A quantitative analysis of the effects of chess instruction on the mathematics achievement of southern, rural, black secondary students

    Get PDF
    This study investigates the effects of chess instruction on the mathematics achievement of a group of southern, rural, black, secondary students. Instruments used included the mathematics section of the CAT (Level 20), Group Embedded Figures Test (GEFT), Matrix Analogies Test-Short Form (MAT-SF), Guilford-Zimmerman Spatial Visualization Test (SV), and Guilford Zimmerman Spatial Orientation Test (SO). The treatment group, which received 18 weeks of chess instruction, consisted of 11 females and 8 males. The control group was comprised of 10 females and 10 males. All participants were high school juniors or seniors. Analysis of variance of the pre-tests found no significant differences between the treatment and control groups. Post-test data were analyzed by 2 x 2 MANCOVA which used statistically significant pre-tests as covariates. The treatment group scored significantly higher than the control group on post-test measures of mathematics achievement, F(1, 38) = 4.14, p3˘c.043;p \u3c .043; field dependence/independence, F(1, 38) = 6.02, p3˘c.019;p \u3c .019; spatial visualization, F(1, 38) = 14.13, p3˘c.001;p \u3c .001; and nonverbal reasoning, F(1, 38) = 6.09, p3˘c.037.p \u3c .037. The control group scored significantly higher on the spatial orientation test, F(1, 38) = 4.22, p3˘c.048.p \u3c .048. Further analysis by one-way ANCOVA found that only female members of the treatment group scored significantly higher on measures of mathematics achievement. Factor analysis extracted only one variable from the five instruments used in the study. This variable was labeled Spatially Based Cogntion (SBC). One-way ANCOVA of this extracted variable also found that only the treatment group females scored significantly higher than the control group females. No significant difference was found between the treatment group males and control group males for the extracted variable

    Forthcoming Papers

    Get PDF
    corecore