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11.
The degree of reciprocity of a proximity order is the proportion, P(1), of elements for which the closest neighbor relation is symmetric, and the R value of each element is its rank in the proximity order from its closest neighbor. Assuming a random sampling of points, we show that Euclidean n-spaces produce a very high degree of reciprocity, P(1) ≥ 12, and correspondingly low R values, E(R) ≤ 2, for all n. The same bounds also apply to homogeneous graphs, in which the same number of edges meet at every node. Much less reciprocity and higher R values, however, can be attained in finite tree models and in the contrast model in which the “distance” between objects is a linear function of the numbers of their common and distinctive features.  相似文献   
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A linear utility model is introduced for optimal selection when several subpopulations of applicants are to be distinguished. Using this model, procedures are described for obtaining optimal cutting scores in subpopulations in quota-free as well as quota-restricted selection situations. The cutting scores are optimal in the sense that they maximize the overall expected utility of the selection process. The procedures are demonstrated with empirical data.  相似文献   
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The responsiveness of mothers to their infants has been found to make an important contribution to children's development. Mothers' cognitive ability, emotional state, and life stresses may influence their responsiveness, as may the medical condition of their infants. The patterns of influence may vary between groups of children with different biological risk conditions and should be examined carefully to determine intervention points for different groups. Forty mothers and their 3-month-old (corrected age) infants with intraventricular hemorrhage (IVH) were observed in free play. Mothers' depressive symptoms, cognitive skills, and the degree of infants' IVH were assessed and expected to be influences on mothers' responsiveness. Results indicated that mothers' depressive symptoms and cognitive skills were associated with their responsiveness, but that depressive symptoms were the stronger predictor. Post hoc analyses suggested that socioeconomic status and depressive symptoms may have related effects on mothers' behavior.  相似文献   
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This study examined individuals' memory for the temporal order of autobiographical events and for the components that constitute autobiographical events. Study 1 measured performance on an across-event ordering task that involved the chronological arrangement of cards that displayed event labels. Results indicated poor ordering ability across events, but a reasonable ability to order clusters of events. Study 2 compared within-event and across-event ordering using computer-presented digital photographs. Participants were better at ordering the photographs in their own across-event trials than in their within-event trials. The results are discussed in terms of the retrieval of temporal information under within- and across-event conditions.  相似文献   
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To investigate the cognitive functioning of children and adolescents with bipolar illness, 112 child and adolescent psychiatric inpatients and day-hospital patients at a state psychiatric hospital were administered the Wechsler Intelligence Scale for Children-III (WISC-III) as part of an admission psychological assessment. There were 22 patients with Bipolar Disorder and 90 with other psychiatric disorders; all were between 8 and 17 years of age. The patients with Bipolar Disorder had a mean age of 14 yr., a mean Verbal IQ of 78, a mean Performance IQ of 76, and a mean Full Scale IQ of 75. When their WISC-III scores were compared with those who had Schizophrenia Spectrum disorders (Schizophrenia and Schizoaffective Disorder), Psychosis Not Otherwise Specified, Attention Deficit Hyperactivity Disorder, and Conduct Disorder and Oppositional Defiant Disorder, there were no significant between-group mean differences for Verbal IQ, but patients with Bipolar Disorder had a significantly lower mean Performance IQ than those with ADHD and those with Conduct Disorder and Oppositional Defiant Disorder. Contrary to the expectation that the patients with Bipolar Disorder might have better sustained attention (higher Digit Span scores) than those with Schizophrenia Spectrum disorders and worse visual processing speed (lower Coding scores) than the other diagnostic groups, the bipolar patients' Digit Span and Coding scores did not differ significantly from those of the other groups. The patients with Psychosis, Not Otherwise Specified had significantly lower mean Performance IQ, Full Scale IQ, and Coding than the ADHD and the Conduct Disorder and Oppositional Disorder groups.  相似文献   
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This study investigated the reciprocal relationship between perceptions of psychological contract fulfilment and employee performance (sales made and sales targets), and whether this was moderated by the quality and length of the social exchange relationship captured, respectively, through perceived organizational support (POS) and organizational tenure. We used a sample of 146 sales advisors and a four‐point longitudinal design and found support for reciprocal links where performance predicted subsequent psychological contract fulfilment and vice versa. The strength of the relationship between performance and psychological contract fulfilment increased over time. The quality of the social exchange relationship (i.e., POS) moderated reciprocal links between sales made and sales targets met and perceptions of psychological contract fulfilment at earlier, but not later, time points. One way to interpret the findings is the changing nature of the unfolding relationship between support, psychological contract fulfilment, and performance, where a supportive relationship buffers failing to deliver at earlier time points, but at later time points employee performance and psychological contract fulfilment associate more strongly as both parties prioritize delivery.  相似文献   
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The serial reaction time (SRT) task is a simple procedure in which participants produce differentiated responses to each of a series of stimuli presented at varying locations. Learning about stimulus order is revealed through decreased latencies for structured versus randomized sequences. Although widely used with humans and well suited to nonhumans, this paradigm is little used in comparative research. In the present article, we describe an SRT procedure that uses colored circles as stimuli, a circular layout of locations, and symmetrical joystick deflections as responses. In two experiments, we showed that four rhesus macaques (Macaca mulatta) learned to track sequences up to eight items long, with three animals showing faster responding to repeating sequences than to randomized versions. After extended training, these participants also showed evidence of faster responding at all positions within repeating sequences. This method minimizes response effort, equates effort and travel distance across stimulus locations, and is applicable to any joystick-capable species.  相似文献   
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