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期望反应模式是认知诊断分类的类中心,确定了诊断范围中属性及其层级关系后,类中心的数目由测验Q矩阵决定.类中心应该是完备的,即理论上有多少个知识状态就应该有多少个类中心,这涉及评分方式、Q矩阵设计、Q矩阵评价与修改、认知诊断测验如何实施等问题的讨论.重点给出多级评分认知诊断测验不同属性层级对应的完备Q矩阵设计的例子和罗列了Wang等人(2013)的Q矩阵修改的方法.  相似文献   

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In the typical visual laterality experiment, words and letters are more rapidly and accurately identified in the right visual field than in the left. However, while such studies usually control fixation, the deployment of visual attention is rarely restricted. The present studies investigated the influence of visual attention on the visual field asymmetries normally observed in single-letter identification and lexical decision tasks. Attention was controlled using a peripheral cue that provided advance knowledge of the location of the forthcoming stimulus. The time period between the onset of the cue and the onset of the stimulus (Stimulus Onset Asynchrony—SOA) was varied, such that the time available for attention to focus upon the location was controlled. At short SO As a right visual field advantage for identifying single letters and for making lexical decisions was apparent. However, at longer SOAs letters and words presented in the two visual fields were identified equally well. It is concluded that visual field advantages arise from an interaction of attentional and structural factors and that the attentional component in visual field asymmetries must be controlled in order to approximate more closely a true assessment of the relative functional capabilities of the right and left cerebral hemispheres.  相似文献   

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After nearly three decades of discussion about sustainable development are we any nearer to achieving it? And do we even know what a sustainable world will look like for future generations? Early definitions of sustainable development were so broad as to allow a range of interpretations based largely on individual interests and anthropocentric needs. We are measuring the performance of countless indicators of sustainable development, but is this more an exercise in applying data than meaningful progress? This article explores the ultimate goals of sustainable development and the most important means of achieving this by analyzing and comparing two frameworks designed to direct attention to the fundamental means and the ends of sustainable development.  相似文献   

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Ethical notions such as good and bad, are often treated as though they were ‘symmetric’ in the sense of having the same moral ‘weight’, one in a positive the other in a negative sense. I argue that they are in fact ‘asymmetric’ and that the negative members of such pairs of notions are more fundamental and definite, logically speaking, and operationally more important than the positive members. Detailed arguments are given to show this for some non‐moral notions, such as life and death, health and illness; some semi‐moral notions such as pleasure and pain; and finally for the moral notions of happiness, benevolence, right, and good and their negative counterparts. One of the intentions of the article is to show that a systematic view of such asymmetries may have consequences for one's view of the proper or desirable structure of a general theory of ethics: norms stating prohibitions and norms stating permissions will be seen to be, in a sense defined in the text, more fundamental and important than norms stating ('positive') obligations.  相似文献   

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The origins and nature of hemispheric specialization of action control are unclear. A review of some recent evidence suggests that the right hemisphere interprets spatial relationships whereas the left deals with temporal control of movement. Contrary to the popular view, specialization of the right hemisphere for spatial representations might have preceded left hemisphere specialization for language and movement.  相似文献   

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In this article, we address the apparent discrepancy between causal Bayes net theories of cognition, which posit that judgments of uncertainty are generated from causal beliefs in a way that respects the norms of probability, and evidence that probability judgments based on causal beliefs are systematically in error. One purported source of bias is the ease of reasoning forward from cause to effect (predictive reasoning) versus backward from effect to cause (diagnostic reasoning). Using causal Bayes nets, we developed a normative formulation of how predictive and diagnostic probability judgments should vary with the strength of alternative causes, causal power, and prior probability. This model was tested through two experiments that elicited predictive and diagnostic judgments as well as judgments of the causal parameters for a variety of scenarios that were designed to differ in strength of alternatives. Model predictions fit the diagnostic judgments closely, but predictive judgments displayed systematic neglect of alternative causes, yielding a relatively poor fit. Three additional experiments provided more evidence of the neglect of alternative causes in predictive reasoning and ruled out pragmatic explanations. We conclude that people use causal structure to generate probability judgments in a sophisticated but not entirely veridical way.  相似文献   

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Several forms of symmetry in degrees of evidential support areconsidered. Some of these symmetries are shown not to hold in general. This has implications for the adequacy of many measures of degree ofevidential support that have been proposed and defended in the philosophical literature.  相似文献   

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The aim of this study was to determine whether the referential term on the horizontal dimension corresponds to the dominant hand and whether the referential term on the vertical dimension is independent of handedness. In order to verify the hypothesis, right-handers, left-handers, and ambidextrous subjects were required to verify and falsify statements including the words ABOVE and BELOW and the words LEFT and RIGHT. The results showed that right-handers were faster in verifying and falsifying the statements containing the term RIGHT, whereas left handers were faster in verifying and falsifying those containing the term LEFT. Ambidextrous subjects, however, showed no sign of asymmetry in the positional judgments of stimuli along the horizontal dimension. By contrast, right-handers, left-handers, and ambidextrous subjects were equally faster in verifying and falsifying the statements containing the term ABOVE than the statements containing the term BELOW. The relation between the positive term on the horizontal dimension and the dominant hand can be explained by the fact that, in the absence of any asymmetries in the physical world, the dominant hand can furnish a natural reference direction for judgments related to this dimension.  相似文献   

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It is often said that while we have a strong reason not to create someone who will be badly off, we have no strong reason for creating someone who will be well off. In this paper I argue that this asymmetry is incompatible with a plausible principle of independence of irrelevant alternatives, and that a more general asymmetry between harming and benefiting is difficult to defend. I then argue that, contrary to what many have claimed, it is possible to harm or benefit someone by bringing her into existence.  相似文献   

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Models of interlimb coordination (H. Haken, J. A. S. Kelso, &; H. Bunz, 1985 Haken, H., Kelso, J. A. S. and Bunz, H. 1985. A theoretical model of phase transitions in human hand movements. Biological Cybernetics, 51: 347356. [Crossref], [PubMed], [Web of Science ®] [Google Scholar]; P. N. Kugler &; M. T. Turvey, 1987 Kugler, P. N. and Turvey, M. T. 1987. Information, natural law, and the self-assembly of rhythmic movement, Hillsdale, NJ: Erlbaum.  [Google Scholar]) were tested in walking by examining the role of asymmetries between limbs. Participants walked on a treadmill with and without a metronome. Five asymmetry conditions were created via ankle loads of 0, 3, or 6 kg on either leg. With the metronome, participants matched the target period. Without the metronome, stride rate slowed as the mass was increased on either leg. The loads led to an increase in stride period that was predicted by Huygens’ law and the hybrid pendulum-spring model. In agreement with extended Haken–Kelso–Bunz model predictions, leg asymmetries led to deviations from antiphase coordination. Also, perception–action coordination was influenced by the asymmetry between the legs and metronome. In contrast, no predicted stability effects were observed. These findings reveal that some properties of interlimb coordination, apparent in laboratory-based tasks, can also be observed in human walking.  相似文献   

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In visual search tasks, observers look for a target stimulus among distractor stimuli. A visual search asymmetry is said to occur when a search for stimulus A among stimulus B produces different results from a search for B among A. Anne Treisman made search asymmetries into an important tool in the study of visual attention. She argued that it was easier to find a target that was defined by the presence of a preattentive basic feature than to find a target defined by the absence of that feature. Four of the eight papers in this symposium inPerception & Psychophysics deal with the use of search asymmetries to identify stimulus attributes that behave as basic features in this context. Another two papers deal with the long-standing question of whether a novelty can be considered to be a basic feature. Asymmetries can also arise when one type of stimulus is easier to identify or classify than another. Levin and Angelone’s paper on visual search for faces of different races is an examination of an asymmetry of this variety. Finally, Previc and Naegele investigate an asymmetry based on the spatial location of the target. Taken as a whole, these papers illustrate the continuing value of the search asymmetry paradigm.  相似文献   

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Displacing an object with a hand-held rod provided a simple paradigm for studying tool use. The authors asked how reaching was affected by manipulations of rod properties. Adults held a rod (length = .10 to 1.5 m), with its tip in the air; walked toward an object on a table; chose a place to stop; and displaced the object with the rod's tip. In 3 experiments (Ns = 9, 22, and 17 participants), the authors manipulated rod length, mass, and mass distribution to determine whether and how geometric and dynamic properties affected the chosen distance and the posture. Both the chosen stopping distance and the postures were well accommodated to rod characteristics. Postural adaptations took place only in the arm, which was organized as a synergy. Predictably, rod length explained most of the variance, but small and reliable differences in both distance and posture depended on mass and mass distribution. The chosen distance anticipated not only rod length but also the upcoming posture needed to control the rod.  相似文献   

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This study was designed to examine the contribution of the right cerebral hemisphere in the spatial localization of visual targets for manual aiming. Visual targets were briefly presented to the right and left fields and subjects were required to point either to the target location, or a "mirror" image of the target location with their right or left index finger. Whereas reaction times were faster for left-hand pointing than for right-hand pointing, there was no differential effect of the mirror image transformation. This suggests that left-hand reaction time advantages are more related to right hemisphere involvement in the spatial parameterization of the movement than spatial localization of the target.  相似文献   

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Hemispace asymmetries and laterality effects were examined on an arm positioning reproduction task. Sixteen male subjects were asked to reproduce both abductive and adductive positioning movements with the left or right arm within either the left or the right hemispace. Hemispace was manipulated using a 90 degrees head-rotation paradigm. A left hemispace advantage in positioning accuracy was predicted for both left and right arm movements on the grounds that the perceptual-motor control of positioning movements made in left hemispace is primarily mediated by the right hemisphere which is known to be advantageous for tasks which are spatial in nature (Heilman, Bowers, & Watson, 1984). No arm laterality effects were predicted to occur because the proximal musculature involved in the control of arm movements is innervated from both contralateral and ipsilateral cerebral hemispheres (Brinkman & Kuypers, 1973). Results showed that the predicted left hemispace advantage was evident for the right arm on the positioning variability measure alone, whereas it was absent for all other possible conditions on all error measures. Laterality (arm) effects were absent as predicted. The experiment also demonstrated a greater degradation of reproduction performance under the ′crossed" arm-hemispace conditions than under the ′uncrossed" conditions. A plausible explanation for the uncrossed advantage for the task is that under normal conditions, a single hemisphere is primarily responsible for both controlling the contralateral arm and directing attention to the contralateral hemispace, and consequently potential interhemispheric interference is minimized. A clear response bias effect in movement reproduction was also evident as a function of the direction of concurrent arm movement and head rotation. Arm movements made in the same direction as head rotation were systematically undershot in reproduction to a much greater degree than arm movements made in the opposite direction to head rotation.  相似文献   

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The influence of information-based dynamics on coordination dynamics of rhythmic movement was examined with special reference to the expression of asymmetries. In Experiment 1, right-handed subjects performed unimanual, rhythmical movements in coordination with either a discrete or continuous visual display. The right hand-visual display system defined a more stable perception-action collective than the left, particularly when continuous visual information was available. In Experiment 2, the same subjects performed rhythmic bimanual movements in coordination with a continuous visual display. The action collective was inherently more stable than the perception-action collective, although similar patterns were observed at both levels. Importantly, the dynamics of the perception-action collective impinged upon the dynamics of the action collective in terms of stability. Asymmetries remained evident between limbs in the bimanual preparations, with the left hand exhibiting greater limit-cycle variability and also a tendency to more often effect transitions at the action couple. Features of dynamical models that capture characteristics of manual asymmetries are discussed.  相似文献   

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