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1.
Donald Campbell’s approach to causal inference (D. T. Campbell, 1957; W. R. Shadish, T. D. Cook, & D. T. Campbell, 2002) is widely used in psychology and education, whereas Donald Rubin’s causal model (P. W. Holland, 1986; D. B. Rubin, 1974, 2005) is widely used in economics, statistics, medicine, and public health. Campbell’s approach focuses on the identification of threats to validity and the inclusion of design features that may prevent those threats from occurring or render them implausible. Rubin’s approach focuses on the precise specification of both the possible outcomes for each participant and assumptions that are mathematically sufficient to estimate the causal effect. In this article, the authors compare the perspectives provided by the 2 approaches on randomized experiments, broken randomized experiments in which treatment nonadherence or attrition occurs, and observational studies in which participants are assigned to treatments on an unknown basis. The authors highlight dimensions on which the 2 approaches have different emphases, including the roles of constructs versus operations, threats to validity versus assumptions, methods of addressing threats to internal validity and violations of assumptions, direction versus magnitude of causal effects, role of measurement, and causal generalization. The authors conclude that investigators can benefit from drawing on the strengths of both approaches in designing research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

2.
Improving mathematics and science education in the United States has been a matter of national concern for over half a century. Psychology has a vital role to play in this enterprise. In this article, the authors review the kinds of contributions that psychology can make in four areas: (a) early understanding of mathematics, (b) understanding of science, (c) social and motivational aspects of involvement in mathematics and science, and (d) assessment of learning in mathematics and science. They also examine challenges to psychology’s playing a central and constructive role and make recommendations for overcoming those challenges. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

3.
Causality plays a fundamental role in scientific explanation. This introduction describes 2 target articles and 3 commentaries on 2 influential perspectives on causal inference, one developed by Donald Campbell and the other developed by Donald Rubin. One goal of this special section is to introduce Rubin’s causal model to psychologists who may be largely unfamiliar with it. Another goal is to compare Rubin’s conceptualization with Campbell’s perspective, to enrich readers’ understanding of both views. All of the authors of this special section perceive many similarities between the 2 approaches. Even so, by comparing and contrasting the 2 perspectives, the authors also believe that it is possible to strengthen both approaches. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

4.
Parkinson’s disease (PD) involves facial masking, which may impair social interaction. Older adult observers who viewed segments of videotaped interviews of individuals with PD expressed less interest in relationships with women with higher masking and judged them as less supportive. Masking did not affect ratings of men in these domains, possibly because higher masking violates gender norms for expressivity in women but not in men. Observers formed less accurate ratings of the social supportiveness and social strain of women than men, and higher masking decreased accuracy for ratings of strain. Results suggest that some of the problems with social relationships in PD may be due to inaccurate impressions and reduced desire to interact with individuals with higher masking, especially women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

5.
β-Ti bio-alloys with low Young’s moduli (E) require multiple alloying using both BCC stabilizers and low-E elements. In this study, the cluster-plus-glue-atom model was introduced in the composition interpretation and design of Ti-based (Ti,Zr)-(Mo,Sn)-Nb alloys. Alloying elements are grouped according to their enthalpies of mixing with Ti, forming a general cluster formula [(Mo,Sn)(Ti,Zr)14]Nb1 or 3, where the square brackets enclose the nearest neighbor coordination polyhedron cluster CN14 of the BCC structure and Nb is the glue atom. The formulated compositions could reach simultaneously low E and high β-Ti structural stabilities, as exemplified by [(Mo0.5Sn0.5)(Ti13Zr)]Nb1 which had a Young’s modulus as low as 48 GPa in the suction-cast state.  相似文献   

6.
Difficulties in understanding emotional signals might have important implications for social interactions in old age. In this study we investigated emotion perception skills involved in decoding facial expressions of emotion in healthy older adults, compared with those with Alzheimer’s disease (AD) or late-life mood disorder (MD). Although those with MD were mildly impaired in identifying emotional expressions, this was not caused by negative biases in choosing labels. Emotion decoding performance in AD was much more impaired, particularly when relatively subtle expressions were presented. Difficulties in choosing between labels to describe an emotional face were predicted by executive dysfunction, whereas impaired ability to match 2 emotional faces was related to general difficulties with face perception. Across all 3 groups, problems with emotion perception predicted quality of life independently of variance predicted by cognitive function and mood, indicating the potential importance of emotion decoding skills in the well-being of older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

7.
The behavior of Young’s modulus, E, was determined in aluminum alloys such as AA7075 and AA2024 at room temperature under various thermomechanical treatments. E was almost 2 pct (AA7075) and 3 pct (AA2024) lower for these materials after solution heat treatment and quenching than after annealing. When the aging time was increased, values of E tended to approach the annealing values. The variation observed was attributed to structural changes during the thermal treatments. However, when the alloys were cold deformed before or after aging, no appreciable changes in E were observed. This behavior is quite different to that observed in cold-worked pure aluminum (and also in pure iron), in which E decreased to a minimum (7 to 10 pct reduction in values) and then partially recovered with additional cold working. The variation in behavior with cold working observed in a pure material and other materials that contain a second phase with nanometric precipitates was correlated with the density of dislocations and the length of the dislocation segments generated during the cold working process.  相似文献   

8.
Individuals with Parkinson’s disease (PD) have shown deficits in the ability to recognize emotion. However, these results have been inconsistent. In addition, questions remain about whether any deficit in PD is secondary to depression and broader cognitive impairments, and the effects of stimulus modality, task type, and specific emotion remain unclear. A meta-analysis of 34 comparisons, using data from 1,295 individual participants, was conducted to (a) provide a reliable estimate of the magnitude of the purported deficit in emotion recognition and (b) examine the influence of several potential moderators of emotion recognition abilities in PD. Results show a robust link between PD and specific deficits in recognizing emotion, from both the face and the voice (overall effect size g = 0.52). The deficit extends across stimulus modalities and task types and is particularly acute with respect to negative emotions. Although this deficit does not appear to be secondary to comorbid depression or visuospatial impairments, the potential role of working memory constraints warrants further investigation. We highlight the potential implications of these findings for communication abilities in PD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

9.
We examined instructed and spontaneous emotion regulation in patients with frontotemporal lobar degeneration (FTLD, N = 32), which presents with profound emotional and personality changes; patients with Alzheimer’s disease (AD, N = 17), which presents with profound memory impairment; and neurologically normal controls (N = 25). Participants were exposed to an aversive acoustic startle stimulus (115 dB) under 3 different conditions: (a) unwarned without instructions to down-regulate, (b) warned without instructions to down-regulate, and (c) warned with instructions to down-regulate. In the last 2 conditions, the warning took the form of a 20-s countdown. In all conditions, visible aspects of the startle response were assessed by measuring overall somatic activity and coding emotional facial expressions. FTLD patients, AD patients, and control participants showed similar patterns of down-regulation in somatic activity across the 3 startle trials. However, differences between the 3 groups emerged in the amount of emotional facial behavior expressed in the startle trials. There were no group differences in response in the unwarned condition, indicating that the startle response was intact in the patients. In the warned with instructions condition, both FTLD and AD patients were moderately impaired in down-regulatory ability compared with controls. In the warned without instructions condition, AD patients and normal controls spontaneously down-regulated their emotional responses, but FTLD patients did not. These findings illuminate specific problems that these patients have in the emotional realm. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

10.
EfectsofCeandImpuritiesonPercentageElongationandRecrystalizationinAlLiAloysMengLiang(孟亮)(DepartmentofMaterialsScienceandEng...  相似文献   

11.
In this paper, the thermodynamic model of nitrogen solubility in vanadium nitrogen microalloyed high strength weathering steels of Fe–Cr–Mn–V–N system, according to Hillert’s model for Gibbs energy of its various phases, was established and validated. In the model, the effect of the nitrogen partial pressure on the activity coefficient and the lattice structure characteristics of the vanadium nitrogen precipitated phase were considered. It would be of guiding significance for the design and smelting of Fe–Cr–Mn–V–N system alloys. Based on the established model, the nitrogen contents in \(\delta\), \(\gamma\), \(\alpha\) phase and liquid were calculated as a function of the temperature for Fe–Cr–Mn–V–N system alloys. The results show that: first, the maximum solubility of nitrogen in the solidification process is obviously affected by the phase transition when there is a sudden change in the solubility of nitrogen at the phase transition point. The maximum nitrogen solubility of the molten steel in the delta phase region determines whether nitrogen bubbles are formed during the solidification process. The nitrogen solubility is lowest in the solid–liquid region (about 1673 K). Secondly, the increase of Cr and Mn content is beneficial to improve nitrogen solubility in liquid and solid phases. However, the increase of V content mainly affects the nitrogen solubility in the solid phase because the nitrogen in this temperature range is precipitated in the form of vanadium nitride, as the second phase plays a role in strengthening. In addition, the alloying element Mn has a significant effect on nitrogen solubility since the Mn element is the promoting element of austenitic formation. During the solidification process, the delta ferrite region gradually reduces and may disappear with increasing Mn content. Therefore, increasing the Mn content of the alloy system in the design of alloy composition, can reduce the precipitation trend of the nitrogen during the solidification process, which can effectively avoid bubble formation in high nitrogen weathering steels. Lastly, with the increase in the nitrogen partial pressure, the solubility of nitrogen increases during the liquid and solid phases.  相似文献   

12.
Fromthepresentknowledgeofmelting[1-3]itisknownthatthefirsteventatimmersingacoldsolidbodyintoahotmeltistheformationofashelloffrozenmeltaroundthebody.Shellformationdoesalsooccur,ifapieceofacoldalloyisthrownintoahotmelt.Inthecasethatthealloyhasalowerliq…  相似文献   

13.
This short article is a commentary on a research study investigating therapist and client attachment styles and their relationship to alliance development in a 12-week psychodynamic psychotherapy program for nonpsychotic inpatients. The relationship is complex; unsurprisingly, securely attached therapists with less distressed clients formed the strongest alliances. A significant proportion of therapists were insecure, almost entirely in the preoccupied or hyperactivating mode. It is argued that collusive relationships between such therapists and similarly overaroused clients may be common. Therapists need both to accommodate to their client’s attachment style and to confound it if positive change is to result. Therapist self-scrutiny is likely to be a precondition for such positive outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

14.
Bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson’s disease (PD) can produce emotional disorders that have been linked to disturbance of the STN’s limbic territory. The aim of this study was to confirm the impairment of the recognition of facial emotions (RFE) induced by STN DBS, not only ruling out the effect of the disease’s natural progression in relation to the effect of DBS, but also assessing the influence of modifications in dopamine replacement therapy (DRT) following STN DBS. RFE was investigated in 24 PD patients who underwent STN DBS and 20 PD patients treated with apomorphine. They were assessed 3 months before and after treatment. The 2 patient groups were compared with a group of 30 healthy matched controls. The results showed that RFE for negative emotions (fear and sadness) was impaired in only the STN DBS group in the posttreatment condition and was unrelated to DRT. Results confirm the selective reduction of RFE induced by STN DBS, due neither to the disease’s natural progression nor to modifications in DRT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

15.
Metallurgical and Materials Transactions A - The limits of occurrence and the morphology of martensite in Cu-Zn-Al alloys with 30 to 50 wt pct Zn and ≤ 1.5 wt pct Al...  相似文献   

16.
Powder Metallurgy and Metal Ceramics - Zirconium boride–nichrome (Ni–20 Cr) interaction at zirconium boride concentration in the charge varying from 3.6 to 60% and at annealing...  相似文献   

17.
In this study, the authors examined the extent to which children’s self-regulation upon kindergarten entrance and classroom quality in kindergarten contributed to children’s adaptive classroom behavior. Children’s self-regulation was assessed using a direct assessment upon entrance into kindergarten. Classroom quality was measured on the basis of multiple classroom observations during the kindergarten year. Children’s adaptive classroom behavior in kindergarten was assessed through teacher report and classroom observations: Teachers rated children’s cognitive and behavioral self-control and work habits during the spring of the kindergarten year; observers rated children’s engagement and measured off-task behavior at 2-month intervals from November to May. Hierarchical linear models revealed that children’s self-regulation upon school entry in a direct assessment related to teachers’ report of behavioral self-control, cognitive self-control, and work habits in the spring of the kindergarten year. Classroom quality, particularly teachers’ effective classroom management, was linked to children’s greater behavioral and cognitive self-control, children’s higher behavioral engagement, and less time spent off-task in the classroom. Classroom quality did not moderate the relation between children’s self-regulation upon school entry and children’s adaptive classroom behaviors in kindergarten. The discussion considers the implications of classroom management for supporting children’s early development of behavioral skills that are important in school settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

18.
As the demographics of U.S. society become more diverse, more People of Color are attracted to the fields of counseling/clinical/school psychology and have the opportunity to work with supervisors from ethnically and culturally diverse backgrounds. An African American supervisor reflects on her experiences with multicultural supervision. Seven microaggression themes are discussed, along with three multicultural identity and competence disequilibrium patterns. The author also describes the benefits and challenges of multicultural supervision and the tenure-track process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
Tourette’s syndrome (TS) is a neurodevelopmental disorder linked with frontostriatal dysfunction. Previous work has shown some evidence of mild performance deficits on a range of different tasks that involve inhibitory processes. The present study evaluated this in adult participants with uncomplicated TS. Interference control was measured using the Stroop and flanker tasks and a Stroop–flanker task that combined the inhibitory demands of both. Motor inhibition was measured using a letter continuous performance test (CPT) task and word CPT tasks that manipulated the inhibitory demands using compatible and incompatible words. The TS group was found to be slower than the control group on most measures, but showed differential slowing under conditions with enhanced inhibitory demands on the combined Stroop–flanker and the incompatible CPT tasks. The findings suggest that TS-alone is linked to mild impairments in aspects of inhibitory function, and that these can be detected by relatively powerful inhibitory manipulations. A range of different types of inhibitory tasks may be sensitive to TS-alone, and this may depend on both the type of inhibition and the strength of the inhibitory manipulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
Children’s numerical competence in kindergarten is highly predictive of their acquisition of mathematics in Grade 1 and Grade 2, suggesting that experiences at home before schooling are important in understanding how numeracy develops. In this study, the mathematical skills of 146 children in Kindergarten, Grade 1, and Grade 2 were correlated with the frequency with which parents reported informal activities that have quantitative components such as board and card games, shopping, or cooking. Effect sizes were consistent with research relating home literacy experiences to children’s vocabulary. The present research supports claims about the importance of home experiences in children’s acquisition of mathematics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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