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1.
针对MapReduce任务调度中任务属性取默认值的不合理性以及人为指定值的不确定性,对调度算法实现动态调整任务优先级、计算合理的Reduce任务数、明确Reduce任务启动时机等改进,达到提升任务并行度、缩短作业执行时间的目的.Fair与LATE算法改进前后的实验结果表明,基于任务属性的改进能提高调度算法性能与作业整体执行效率. 相似文献
2.
Melinda R. Snodgrass Hedda Meadan Michaelene M. Ostrosky W. Catherine Cheung 《Early Childhood Education Journal》2017,45(6):855-862
Task analyses are useful when teaching children how to complete tasks by breaking the tasks into small steps, particularly when children struggle to learn a skill during typical classroom instruction. We describe how to create a task analysis by identifying the steps a child needs to independently perform the task, how to assess what steps a child is able to do without adult support, and then decide how to teach the steps the child still needs to learn. Using task analyses can be the key to helping a young child become more independent. 相似文献
3.
Value-based decisions often involve comparisons between benefits and costs that must be retrieved from memory. To investigate the development of value-based decisions, 9- to 10-year olds (N = 30), 11- to 12-year olds (N = 30), and young adults (N = 30) first learned to associate gain and loss magnitudes with symbols. In a subsequent decision task, participants rapidly evaluated objects that consisted of combinations of these symbols. All age groups achieved high decision performance and were sensitive to gain–loss magnitudes, suggesting that required core cognitive abilities are developed early. A cognitive-modeling analysis of performance revealed that children were less efficient in object evaluation (drift rate) and had longer nondecision times than adults. Developmental differences, which emerged particularly for objects of high positive net value, were linked to mnemonic and numerical abilities. 相似文献
4.
Sammy Perone Stephen J. Molitor Aaron T. Buss John P. Spencer Larissa K. Samuelson 《Child development》2015,86(3):812-827
Executive functions enable flexible thinking, something young children are notoriously bad at. For instance, in the dimensional change card sort (DCCS) task, 3‐year‐olds can sort cards by one dimension (shape), but continue to sort by this dimension when asked to switch (to color). This study tests a prediction of a dynamic neural field model that prior experience with the postswitch dimension can enhance 3‐year‐olds' performance in the DCCS. In Experiment 1A, a matching game was used to preexpose 3‐year‐olds (n = 36) to color. This facilitated switching from sorting by shape to color. In 3 , 3‐year‐olds (n = 18) were preexposed to shape. This did not facilitate switching from sorting by color to shape. The model was used to explain this asymmetry. 相似文献
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Formal reasoning has been studied extensively with tasks that have physics or laboratory content. This study compares laboratory and naturalistic content influences on formal reasoning tasks. Ninety 13-, 15-, and 17-year olds received both laboratory and naturalistic content tasks which required ability to control variables. Expectations about the variables in each task were measured. Results revealed that 8 to 20% of the variance in performance was associated with task content. Content effects were shown to reflect expectations about task variables. 相似文献
7.
Children are capable of viewing object ownership as categorical and exclusive, but ownership claims can also vary by degree. This study investigated how children use these different conceptions of ownership in a giving and a taking task. In two studies, 4- to 7-year olds (N = 105) could give and take craft objects that they or another child had found (weaker claim) and made (stronger claim). In Study 1, no additional ownership information was given, and in Study 2 categorical ownership was stated (“these belong to you”). The results showed that children used categorical ownership for their own objects but used ownership strength for the other child's objects, taking more of the found items. 相似文献
8.
Four-, 5-, and 6-year olds (N = 102) observed agents perform a reasoning task that required gathering hidden evidence. An agent who made sound inferences was contrasted with an agent who made either unsound inferences (UI; failed to base conclusion on gathered evidence) or guesses (failed to gather evidence). Four-year olds attributed knowledge to all agents and endorsed their conclusions widely. However, 5- and 6-year olds’ knowledge attributions were mitigated by UI, and 6-year olds neither attributed knowledge to a guesser nor endorsed his conclusions. Notably, parents’ tendency to make evaluativist epistemological judgments—which place value in evidence as a basis for belief—predicted children’s reluctance to learn from and credit knowledge to poor reasoners. Parents’ evaluativist judgments also predicted children’s selective learning about object functions. 相似文献
9.
Previous research yielded conflicting results about when children can accurately assess their epistemic states in different hiding tasks. In Experiment 1, ninety‐two 3‐ to 7‐year‐olds were either shown which object was hidden inside a box, were totally ignorant about what it could be, or were presented with two objects one of which was being put inside (partial exposure). Even 3‐year‐olds could assess their epistemic states in the total ignorance and the complete knowledge task. However, only children older than 5 could assess their ignorance in the partial exposure task. In Experiment 2 with one hundred and one 3‐ to 7‐year‐olds, similar results were found for children under 5 years even when more objects were shown in partial exposure tasks. Implications for children’s developing theory of knowledge are discussed. 相似文献
10.
Nicolas Chevalier 《Child development》2018,89(4):1283-1295
Cognitive effort is costly and this cost likely influences the activities in which children engage. Yet, little is known about how school‐age children perceive cognitive effort. The subjective value of cognitive effort, that is, how valuable or costly effort is perceived, was investigated in seventy‐three 7‐ to 12‐year‐olds using an effort discounting paradigm. In two studies, it varied with task difficulty but not age, was predicted by actual effort engagement but not actual success and related to trait interest in effortful activities and proactive control engagement. Children are sensitive to cognitive effort and use it to guide behaviors, suggesting that poor performance may often reflect reluctance to engage cognitive effort rather than low ability. 相似文献
11.
The present study examined performance on an arithmetic task of increasing difficulty and a frustrating puzzle task for children with ADHD and comparison children. Emotional competence also was investigated in the two groups. Sixty‐four children, 21 previously diagnosed with ADHD, participated. Performance on the arithmetic task was measured in terms of completion and accuracy. Children with ADHD had similar rates of accuracy for all levels of difficulty, but completed fewer problems. Performance on the puzzle task was measured both through completion and persistence. Although children with ADHD persisted for a similar amount of time compared to children without ADHD, they were more likely to quit the task before completion. Children with ADHD also were more likely to report that they became frustrated with the task. Furthermore, they tended to report that in general, they become more frustrated than other children. With regard to emotional competence, children with ADHD did not differ from the comparison children on their reported understanding of their own emotions or attention to emotions; however, children with ADHD reported that they engage in less mood repair. © 2006 Wiley Periodicals, Inc. Psychol Schs 43: 377–386, 2006. 相似文献
12.
Visual perspective taking has attracted research interest as a result of Piagetian formulations regarding its ontogenesis. Some investigators have interpreted failure as a consequence of egocentrism while others have hypothesized task variables as the source of failure. The present study directly compared the effects of a picture selection response with a rotational one. Forty 3-year-olds and forty 4-year-olds were compared on the response modes. Half the children indicated perspective inferences by selecting from a set of photographs while the others rotated a replica. Children were tested on three nonegocentric perspectives. The data were analyzed with a 2(age) × 2(response mode) ANOVA. Significant effects were found for response mode and the age × response interaction. It was concluded that while both 3- and 4-year olds were able to demonstrate perspective-taking competence, the 3-year-olds performed better with the turning task; 4-year-olds were equally successful in either mode. 相似文献
13.
Research on the effects of background music has a long history. Early work was not embedded within a theoretical framework, was often poorly conceptualised and produced equivocal findings. This paper reports two studies exploring the effects of music, perceived to be calming and relaxing, on performance in arithmetic and on a memory task in children aged 10-12. The calming music led to better performance on both tasks when compared with a no-music condition. Music perceived as arousing, aggressive and unpleasant disrupted performance on the memory task and led to a lower level of reported altruistic behaviour by the children. This suggests that the effects of music on task performance are mediated by arousal and mood rather than affecting cognition directly. The findings are discussed in relation to possible practical applications in the primary school and the home. 相似文献
14.
OBJECTIVE: It is widely presumed that when children are hit by peers or siblings, it is not as serious as similar acts between adults or older youth, which would be termed, "assaults" and "violent crimes". The goal of this study was to compare the violent peer and sibling episodes of younger children to those of older youth in terms of their seriousness and association with symptoms that might indicate traumatic effects. METHOD: The study collected reports of past year's violent victimizations and childhood symptoms in a national probability telephone sample of 2030 children and youth ages 2-17. The experiences of 10-17-year olds were obtained via self-reports and those of the 2-9-year olds from caregivers. RESULTS: The younger children's peer and sibling victimizations were not less serious than the older youth on the dimensions of injury, being hit with an object that could cause injury or being victimized on multiple occasions. Younger children and older youth also had similar trauma symptom levels associated with both peer and sibling victimization. CONCLUSION: There was no basis in this study for presuming peer and sibling victimizations to be more benign when they involve younger children. The findings provide justification for being concerned about such peer and sibling violence in schools and families and for counting such victimizations in victimization inventories and clinical assessments. 相似文献
15.
Sue Smedley 《English in Education》1991,25(1):12-20
An important reminder that young children know how stories work, and are therefore able to use bibliographic and literary knowledge as they set about the task of learning to read books with maturity and competence. Sue Smedley shows four and five year olds working in intellectually demanding ways to recreate stories for themselves and argues that young children have a right to the kinds of books and stories which call for intelligent and imaginative responses. 相似文献
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Robert L. Fischer Lance T. Peterson Tirth Bhatta Claudia Coulton 《Journal of Education for Students Placed at Risk》2013,18(2):128-140
Investments in high-quality early care and education have been shown to reap societal benefits across the lives of the children served. A key intervention point is in the lives of 3- to 5-year olds during the period prior to entering kindergarten. Many jurisdictions have developed broad-based prekindergarten initiatives. This study reports on a pilot universal prekindergarten program in 24 sites in the Cleveland, Ohio area. Child assessment data were collected on 204 children from early care classrooms for 3- to 5-year olds across 3 time points by trained observers using 2 standardized instruments. Changes in achievement scores were shown to be significantly predicted by race, parental education level, and whether the family spoke English as a second language, with largest gains shown among children who were most behind at baseline. The findings serve to illuminate the developmental trajectory of children before kindergarten and how data can be used to inform practice and policy. 相似文献
17.
Peter W.H. Lee Felice Lieh Mak 《International Journal of Disability, Development & Education》1984,31(2):128-133
The usefulness of the construct of locus of control in increasing understanding of the adjustment and task performance of physically handicapped children is experimentally demonstrated. Thirty‐six physically handicapped children were assigned to internal and external groups on the basis of their scores on the Nowicki‐Strickland Locus of Control Scale. Comparison of data from teachers' ratings, arithmetic performance and accuracy and choice of distance on a ball‐throw task revealed that, despite comparable intellectual ability, internals significantly exceeded externals in teachers' ratings and arithmetic performance; differences on the ball‐throw task, however, were not significant. Results are discussed in terms of locus of control and intervention possibilities for physically handicapped children. 相似文献
18.
Zuowei Wang John Sabatini Tenaha O’Reilly Gary Feng 《Scientific Studies of Reading》2017,21(2):165-178
Reading is affected by both situational requirements and one’s cognitive skills. The current study investigated how individual differences interacted with task requirements to determine reading behavior and outcome. We recorded the eye movements of college students, who differed in reading efficiency, while they completed a multiple-choice (MC) comprehension test in two within-subject conditions: one in which they read passages and answered MC questions as in a typical reading test and one in which they wrote a summary before answering the MC questions. We found students spent longer time reading the text in the summary-writing condition, resulting in a benefit in the time they spent when answering MC questions. This time benefit was larger for students who had relatively low reading efficiency. These results demonstrated that both task requirements and individual differences can interact to affect reading behavior and performance. Implications for reading practice and assessment are discussed. 相似文献
19.
李建明 《廊坊师范学院学报》2007,23(3):84-86
任务分析是使生物课堂教学设计走向科学化、系统化和正规化的一项重要的教学理论与技术。生物课堂教学任务分析包括：确定学生的起点能力;分析使能目标及其学习类型;分析学习的支持性条件。就任务分析的教学理论和技术,如何应用于中学生物课堂教学设计的实践,做了初步的尝试和探讨。 相似文献
20.
John M. Francisco 《Educational Studies in Mathematics》2013,82(3):417-438
The purpose of this study is to contribute insights into how collaborative activity can help promote students’ mathematical understanding. A group of six high school students (15- to 16-year olds) worked together on a challenging probability task as part of a larger, after-school, longitudinal study on students’ development of mathematical ideas in problem-solving settings. The students solved the problem and produced a valid justification of their solution. This study shows that collaborative activity can help promote students’ mathematical understanding by providing opportunities for students to critically reexamine how they make claims from facts and also enable them to build on one another’s ideas to construct more sophisticated ways of reasoning. Implications for classroom teaching and ideas for future research are also discussed. The study helps address a documented need for a better understanding of how mathematical learning evolves in social settings. 相似文献