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31.
Studies examining the effects of day care are reviewed. Little evidence was found indicating a negative impact on child development. A number of weaknesses in the day care literature were pointed out, including problems of ecological validity and failure to examine for differential effects. Suggestions for future research are made, among them a “natural history” of day care and studies of children who have experienced trauma.  相似文献   
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In Study 1, the effect of making tokens contingent on correct performance of low social position preschoolers on the McCarthy Scales of Children's Abilitieswas examined. Preschoolers in a token reinforcement group scored significantly higher (mean=8 IQ points) than subjects in a control group. In Study 2, the effect of tokens on McCarthyresults was examined as a function of social position in a 2×2 design. The high social position control group scored significantly above the low social position control. The low social position token reinforcement group, however, performed as well as both the high social position control and token reinforcement groups. Use of systematic reinforcement contingencies to reduce test error is discussed.  相似文献   
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Bradley  Richard 《Synthese》1998,116(2):187-229
This paper investigates the role of conditionals in hypothetical reasoning and rational decision making. Its main result is a proof of a representation theorem for preferences defined on sets of sentences (and, in particular, conditional sentences), where an agent’s preference for one sentence over another is understood to be a preference for receiving the news conveyed by the former. The theorem shows that a rational preference ordering of conditional sentences determines probability and desirability representations of the agent’s degrees of belief and desire that satisfy, in the case of non-conditional sentences, the axioms of Jeffrey’s decision theory and, in the case of conditional sentences, Adams’ expression for the probabilities of conditionals. Furthermore, the probability representation is shown to be unique and the desirability representation unique up to positive linear transformation. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
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The accuracy of the two-moment, three-moment, square root, and cube root approximations to the noncentralF distribution was assessed using 7,920 entries from Tiku’s (1967) power tables. Tiku’s tables list exact values of β for α= .005?.05, ν1 = 1?12, ν2 = 2?120, and ?= 0.5?3.0. Analysis of the errors showed generally satisfactory performance for all four approximations. The three-moment approximation was most accurate, registering a maximum error of only .009. The other three approximations had maximum errors of ±.02, except for the square root approximation at ν2 = 2, where maximum errors of .05 occur. Approximation error increased with decreases in ν1 and, less consistently, with increases in ν2. Error was nonmonotonically related to ?. A second investigation explored the accuracy of the approximations at values of αranging from .10 to .90. All four approximations degraded substantially in this situation, with maximum errors ranging from ?.09 to .05. If the analysis is restricted to cases where ν1 τ; 1 and ν2 τ; 2, maximum errors drop to roughly ±.03. We conclude that the approximations perform reasonably well for small αand moderately well for larger values, if certain restrictions are imposed. From a computational standpoint, however, there is little advantage to using approximate as opposed to exact methods unless exact values ofF α are known in advance.  相似文献   
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In category classification tasks, typicality effects are usually found: accuracy and reaction time depend upon distance from a prototype. In this study, subjects learned either verbal or nonverbal dot pattern categories, followed by a lateralized classification task. Comparable typicality effects were found in both reaction time and accuracy across visual fields for both verbal and nonverbal categories. Both hemispheres appeared to use a similarity-to-prototype matching strategy in classification. This indicates that merely having a verbal label does not differentiate classification in the two hemispheres.  相似文献   
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The cognitive-behavioural theory of Obsessive Compulsive Disorder (OCD) proposes that a key factor influencing obsessional behaviour is the way in which the intrusive cognitions are interpreted. The present paper reports an investigation of links between clinical symptoms (of anxiety, depression and obsessionality) and responsibility beliefs. These beliefs include not only measures of general responsibility attitudes (assumptions) but also more specific responsibility appraisals consequent on intrusive cognitions. The characteristics of two new questionnaires specifically designed to measure these beliefs were assessed in patients suffering from Obsessive Compulsive Disorder, in patients suffering from other anxiety disorders and in non-clinical controls. The scales measuring negative beliefs about responsibility were found to have good reliability and internal consistency. Comparisons between criterion groups indicate considerable specificity for both assumptions and appraisals with respect to OCD. There was also good evidence of specificity in the association between responsibility cognitions and obsessional symptoms across groups, and that this association was not a consequence of links with anxiety or depressive symptoms. Although the two measures were correlated, they each made unique contributions to the prediction of obsessional symptoms. Overall, the results are consistent with the hypothesis that responsibility beliefs are important in the experience of obsessional problems.  相似文献   
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Hazardous or harmful alcohol use is very prevalent among the US population. With 15.1 million adults in the United States currently identified as having an alcohol use disorder, identifying hazardous and harmful drinking earlier is necessary for early intervention strategies. The Alcohol Use Disorders Identification Test's (AUDIT) strong psychometric properties lead it to be a screening tool of choice across countries, cultures, and subgroups. A psychometric analysis aggregates all available evidence of reliability and validity to support the use of an instrument for screening, diagnosis, and treatment planning. AUDIT internal consistency for the 10-item total scale was α = 0.817 (n = 247,963). The two-factor model had the most structure validity support and aggregated convergent validity comparisons with other alcohol use assessments ranged from r = 0.578 to r = 0.701. The optimal cutoff score for diagnostic validity was 6/7, rather than the 8 recommended by the AUDIT authors. Clinically appropriate use and interpretation of the AUDIT as well as study limitations and suggestions for future research were discussed.  相似文献   
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