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151.
Randomization-based inference about latent variables from complex samples   总被引:1,自引:0,他引:1  
Standard procedures for drawing inferences from complex samples do not apply when the variable of interest cannot be observed directly, but must be inferred from the values of secondary random variables that depend on stochastically. Examples are proficiency variables in item response models and class memberships in latent class models. Rubin's multiple imputation techniques yield approximations of sample statistics that would have been obtained, had been observable, and associated variance estimates that account for uncertainty due to both the sampling of respondents and the latent nature of. The approach is illustrated with data from the National Assessment for Educational Progress.This research was supported by Grant No. NIE-G-83-0011 of the Office for Educational Research and Improvement, Center for Education Statistics, and Contract No. N00014-88-K-0304, R&T 4421552 from the Cognitive Sciences Program, Cognitive and Neural Sciences Division, Office of Naval Research. It does not necessarily reflect the views of either agency. I am grateful to R. Darrell Bock for calling my attention to the applicability of multiple imputation to the assessment setting; to Albert Beaton and Eugene Johnson for enlightening discussions on the topic; and to Henry Braun, Ben King, Debra Kline, Gary Phillips, Paul Rosenbaum, Don Rubin, John Tukey, Ming-Mei Wang, Kentaro Yamamoto, Rebecca Zwick, and two anonymous reviewers for comments on earlier drafts. Example 4 is based on the analysis of the 1984 National Assessment for Educational Progress reading survey, carried out at Educational Testing Service through the tireless efforts of too many people to mention by name, under the direction of Albert Beaton, Director of NAEP Data Analyses. David Freund, Bruce Kaplan, and Jennifer Nelson conducted additional analyses of the 1984 and 1988 data for the example.  相似文献   
152.
Multiple chemical sensitivity (MCS) is a term used to describe a disorder characterized by a vast array of somatic, cognitive, and affective symptoms, the cause of which is attributed to exposure to extremely low levels of a variety of chemicals. Upon examination of the patient with a diagnosis of MCS, objective physical findings and consistent laboratory abnormalities are typically nonexistent. The concept of MCS has ignited considerable controversy in the fields of toxicology, immunology, allergy, psychology, and neuropsychology. Central to the controversy is the disagreement over the extent to which the manifestation of MCS is mediated by psychological factors. Because of the large number of neuropsychological symptoms associated with a diagnosis of MCS, neuropsychologists are increasingly receiving referrals for the assessment of these patients. It is important, therefore, that neuropsychologists become aware of the variety of clinical issues that must be taken into account when assessing an individual with a diagnosis of MCS. The theoretical and research literature on individuals with a diagnosis of MCS is reviewed here.  相似文献   
153.
谢悦  贾晓明 《心理科学》2021,(4):1004-1011
为探索高校咨询师面临的多重关系伦理情境、决策过程,对访谈17名高校心理咨询师的资料进行分析。结果:常见情境主要包括接送礼物承载的新关系、来访者和咨询师除咨询关系外的师生关系、咨询师与和来访者有关的第三人有关系、咨询师在咨询室之外的场所偶遇来访者、来访者有咨询师的联系方式、来访者和咨询师有身体接触等。决策表现为两种:经验主导型,决策时未意识到处于伦理情境只凭经验决策;伦理主导型,决策时意识到处在伦理情境。结论:高校心理咨询存在一些特殊多重关系,心理咨询师需增加具有伦理意识的决策。  相似文献   
154.
Unemployment is high among individuals with multiple sclerosis (MS). Certain disease variables and demographics have been found to distinguish employed and unemployed individuals. However, these variables only account for 14–20% of the variance. Other factors, such as coping, perceived stress and social support, in the workforce have been proposed, but not yet fully examined. The purpose of the present investigation was to examine the role of known factors associated with unemployment in MS, as well as coping and perceived work stress and social support. Sixty-eight women with MS were asked about their employment status and reasons for leaving. They completed a comprehensive assessment including measures of cognition, disease symptoms, psychological functioning, coping and stress. Consistent with previous findings, certain disease and demographic variables were associated with being unemployed. In particular, women who left work due to their MS were found to be older, had a longer disease duration and progressive course, reported greater disability and fatigue, and performed worse on a cognitive measure. However, we also found that coping style distinguished those who were employed from those who left work due to their MS. In particular, those who left work reported utilizing maladaptive coping mechanisms such as behavioral disengagement and substance use. With regard to perceived work stress and support, individuals who were employed reported that job security and fellow co-workers were more of an uplift than a hassle in their lives, suggesting some benefit in employment. These findings suggest that further consideration be given to role of coping and perception of the benefit of employment among individuals with MS when making recommendations regarding work decisions.  相似文献   
155.
The use of item responses from questionnaire data is ubiquitous in social science research. One side effect of using such data is that researchers must often account for item level missingness. Multiple imputation is one of the most widely used missing data handling techniques. The traditional multiple imputation approach in structural equation modeling has a number of limitations. Motivated by Lee and Cai’s approach, we propose an alternative method for conducting statistical inference from multiple imputation in categorical structural equation modeling. We examine the performance of our proposed method via a simulation study and illustrate it with one empirical data set.  相似文献   
156.
Persons with multiple sclerosis (PwMS) often report problems due to sensory loss and have an inability to appropriately reweight sensory information. Both of these issues can affect individual’s ability to maintain stability when walking under challenging conditions. The purpose of the current study was to determine how gait stability is adapted when walking under challenging sensory conditions where vision and somatosensation at the feet is manipulated. 25 healthy adults and 40 PwMS (15 fallers, 25 non-fallers) walked on a treadmill at their preferred normal walking speed under 3 conditions: normal walking, altered vision using goggles that shifted visual field laterally, and altered somatosensation using shoes with compliant foam soles. Inertial measurement united recorded acceleration at the lumbar and right ankle, and acceleration variability measures were calculated including root mean square (RMS), range, sample entropy (SaEn), and Lyapunov exponents (LyE). A gait stability index (GSI) was calculated using each of the four variability measures as the ratio of lumbar acceleration variability divided by foot acceleration variability in the frontal and sagittal planes. The sagittal and frontal GSIRMS were larger in the somatosensory condition compared to the normal and visual conditions (p < 0.001). The frontal GSISaEn was greater in the visual condition compared to the somatosensory condition (p = 0.021). The frontal and sagittal GSILyE was greater in the somatosensory condition compared to the normal and visual conditions (p < 0.002). The current study showed that HC, MS non-fallers and MS fallers largely adapted to altered sensory feedback during walking in a similar manner. However, MS faller subjects may be more reliant on visual feedback compared to MS non-fallers and HC subjects.  相似文献   
157.
The multiple causal pathways model on the etiology of attention-deficit/hyperactivity disorder (ADHD) is well established. However, developmental implications of the model are not yet sufficiently analyzed. The model implies that critical neural and neuropsychological deviations from normative development precede secondarily developing ADHD symptoms. Cognitive, “cool” inhibitory control (CIC) and reward-related, “hot” functions (RRF) are regarded as neuropsychological basic deficits that indicate independent causal pathways. Both functions involve top-down control networks that undergo major normative developmental changes in the preschool period. We formalized the following assumptions in a path model: (a) CIC and RRF predict change in ADHD symptoms in the preschool period, (b) the reverse is not true, and (c) CIC and RRF independently contribute to this prediction. A community-based sample of 125 (71 boys) preschoolers was assessed at at age 4 and 5 years. At each assessment wave, CIC and RRF were measured by a battery of age-appropriate valid tasks. ADHD symptoms were measured by a clinical parent interview. Evaluation of model fit using manifest maximum likelihood parameter estimation clearly supported the hypothesized path model while controlling for gender of child and maternal education level. Thus, regarding the basic deficits of CIC and RRF, the results add evidence on the developmental implications of the multiple causal pathways model. Our findings point to the potential significance of these early emerging characteristics as indicators of risk and as targets for preventive interventions.  相似文献   
158.
Semantic image segmentation is one of the most challenging tasks in computer vision. In this paper, we propose a highly fused convolutional network, which consists of three parts: downsampling, fused upsampling and multiple predictions. We adopt a VGG-net based downsampling structure, followed by multiple steps of upsampling. Feature maps in each pair of corresponding pooling layers and unpooling layers are combined. We also bring out multiple pre-outputs, each is generated from an unpooling layer by a one-step upsampling operation. Finally, we concatenate these pre-outputs to get the final output. As a result, our proposed network makes high use of the feature information by fusing and reusing features in low layers. In addition, when training our model, we add multiple soft cost functions on pre-outputs and the final output. In this way, we can reduce the loss reduction in backpropagation. We evaluate our model on three public segmentation datasets: CamVid, PASCAL VOC, and ADE20K. We achieve considerable segmentation performance on PASCAL VOC dataset and ADE20K dataset. Especially on CamVid dataset, we achieve state-of-the-art performance.  相似文献   
159.
OECD figures (1998–2002) reveal a sharply increasing flow of foreign workers into European countries. Ethnic diversification has become a generalized matter of fact. At the same time, rapidly developing technology and ‘intellectual globalization’ processes—the world wide web—have also become a reality. This complex cluster of changes has an impact on the perceptions of the self and of the other. Multilayered belongings and paradoxical meanings enter into interethnic relations in sometimes most surprising and unpredictable ways from outside of the boundaries of local communities. But the developments also create new and very positive opportunities for education/schooling and social cohesion. The paper critically examines this changing context and also Europe’s educational responses to the new challenges: the European Socrates programme, the initiatives in the field of intercultural citizenship education and the issue of combating deprivation.
Xavier RuppolEmail:
  相似文献   
160.
This article reports findings of the Würzburg and Göttingen Longitudinal Memory Studies, which focused on children's verbal memory development. The studies started with 102 (German) kindergarten children in Würzburg and 86 second-graders in Göttingen who were tested on various memory measures, including sort-recall, memory capacity, metamemory, and verbal IQ. Assessments were repeated nine times, with adjacent measurement points separated by 6-month time intervals. The main goals of the studies concerned the assessment of utilization deficiencies during the course of strategy development, the analysis of factors influencing the effectiveness of strategy use, and the occurrence of multiple strategy use. Findings confirmed the outcome of previous longitudinal studies in that semantic organization strategies were not always accompanied by superior recall, but utilization deficiency problems were comparably rare. Strategy effectiveness was shown as being affected mainly by memory capacity and by children's tendency to engage in multiple strategy use. However, children did not start to apply multiple strategies effectively until the end of Grade 2.  相似文献   
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