The role of trial tracking in rats’ working memory     

J. S. Cohen  M. Njegovan 《Learning & behavior》1999,27(2):211-220

The experiments reported in the present study tested whether decreasing intertrial intervals (ITIs) intensifies the disruptive effects of increasing retention intervals (RIs) in a delayed conditional discrimination by decreasing the animal’s trial tracking accuracy (Cohen & Armstrong, 1996; Cohen & Roberts, 1996). Rats responded on a fixed ratio (FR) 1 or fixed interval (FI) 10-sec reinforcement schedule at a second light or tone stimulus, S2, when the first light or tone stimulus, S1, had signaled an FI 10-sec or FR 1 schedule, respectively. RIs between S1 and S2 were increased from 3 to 24 sec and never exceeded ITIs that were reduced from 24 to 6 sec. For some rats, the trials were separated from each other by extending the lever at S1 and retracting it at the end of S2 (ITI lever-retracted group). For other, control rats, the lever remained extended throughout the session (lever-extended group, Experiment 1) or was extended and retracted with the onset and offset of each stimulus (RI/ITI lever-retracted group, Experiment 2). The rats under all trial conditions learned to delay leverpressing on the FI 10-sec schedule. Latency to begin leverpressing on the FI 10-sec schedule declined as RIs were increased, but this effect was attenuated in the ITI lever-retracted groups in both experiments, as would be predicted by thetrial tracking hypothesis. Decreasing ITIs from 24 to 6 sec intensified the disruptive effects of increasing RIs from 3 to 6 sec in the RI/ITI lever-retracted group (Experiment 2), as would be predicted by the trial tracking hypothesis.  相似文献   

Making Sense of Number Words and Arabic Digits: Does Order Count More?     

Francesco Sella  Daniela Lucangeli  Roi Cohen Kadosh  Marco Zorzi 《Child development》2020,91(5):1456-1470

The ability to choose the larger between two numbers reflects a mature understanding of the magnitude associated with numerical symbols. The present study explores how the knowledge of the number sequence and memory capacity (verbal and visuospatial) relate to number comparison skills while controlling for cardinal knowledge. Preschool children’s (N = 140, M_{age-in-months} = 58.9, range = 41–75) knowledge of the directional property of the counting list as well as the spatial mapping of digits on the visual line were assessed. The ability to order digits on the visual line mediated the relation between memory capacity and number comparison skills while controlling for cardinal knowledge. Beyond cardinality, the knowledge of the (spatial) order of numbers marks the understanding of the magnitude associated with numbers.  相似文献   

A Comparison of Aggregation Rules for Selecting Anchor Items in Multigroup DIF Analysis     

Thorben Huelmann  Rudolf Debelak  Carolin Strobl 《Journal of Educational Measurement》2020,57(2):185-215

This study addresses the topic of how anchoring methods for differential item functioning (DIF) analysis can be used in multigroup scenarios. The direct approach would be to combine anchoring methods developed for two-group scenarios with multigroup DIF-detection methods. Alternatively, multiple tests could be carried out. The results of these tests need to be aggregated to determine the anchor for the final DIF analysis. In this study, the direct approach and three aggregation rules are investigated. All approaches are combined with a variety of anchoring methods, such as the “all-other purified” and “mean p-value threshold” methods, in two simulation studies based on the Rasch model. Our results indicate that the direct approach generally does not lead to more accurate or even to inferior results than the aggregation rules. The min rule overall shows the best trade-off between low false alarm rate and medium to high hit rate. However, it might be too sensitive when the number of groups is large. In this case, the all rule may be a good compromise. We also take a closer look at the anchor selection method “next candidate,” which performed rather poorly, and suggest possible improvements.  相似文献   

Auswahlbibliografie Neuerscheinungen     

Rudolf Tippelt 《Zeitschrift für Erziehungswissenschaft》2009,12(1):159-164

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Examining type I error and power for detection of differential item and testlet functioning     

Young-Sun Lee  Allan Cohen  Maritsa Toro 《Asia Pacific Education Review》2009,10(3):365-375

In this study, the effectiveness of detection of differential item functioning (DIF) and testlet DIF using SIBTEST and Poly-SIBTEST were examined in tests composed of testlets. An example using data from a reading comprehension test showed that results from SIBTEST and Poly-SIBTEST were not completely consistent in the detection of DIF and testlet DIF. Results from a simulation study indicated that SIBTEST appeared to maintain type I error control for most conditions, except in some instances in which the magnitude of simulated DIF tended to increase. This same pattern was present for the Poly-SIBTEST results, although Poly-SIBTEST demonstrated markedly less control of type I errors. Type I error control with Poly-SIBTEST was lower for those conditions for which the ability was unmatched to test difficulty. The power results for SIBTEST were not adversely affected, when the size and percent of simulated DIF increased. Although Poly-SIBTEST failed to control type I errors in over 85% of the conditions simulated, in those conditions for which type I error control was maintained, Poly-SIBTEST demonstrated higher power than SIBTEST.  相似文献   

Tasks, topics and relevance judging for the TREC Genomics Track: five years of experience evaluating biomedical text information retrieval systems     

Phoebe M. Roberts  Aaron M. Cohen  William R. Hersh 《Information Retrieval》2009,12(1):81-97

With the help of a team of expert biologist judges, the TREC Genomics track has generated four large sets of “gold standard” test collections, comprised of over a hundred unique topics, two kinds of ad hoc retrieval tasks, and their corresponding relevance judgments. Over the years of the track, increasingly complex tasks necessitated the creation of judging tools and training guidelines to accommodate teams of part-time short-term workers from a variety of specialized biological scientific backgrounds, and to address consistency and reproducibility of the assessment process. Important lessons were learned about factors that influenced the utility of the test collections including topic design, annotations provided by judges, methods used for identifying and training judges, and providing a central moderator “meta-judge”.  相似文献   

Between education and care? Critical reflections on early childhood policies in Germany     

Hans Rudolf Leu  Regine Schelle 《Early Years: An International Journal of Research and Development》2009,29(1):5-18

This article identifies the responsibilities for early childhood care and education (ECCE) in the German child and youth welfare system and shows the expansion of children's services. The official German statistics demonstrate that almost every child from the age of three to school age attends ‘Kindergarten’. Current policies and measures are therefore mainly focused on extending provision for the under‐threes. There are still enormous differences in the number of places available for children under three years of age between the eastern and western parts of Germany. Due to the increased significance of early education and the educational curricula drafted in all 16 Länder over the past few years, the qualifications required of professional pedagogues today have changed considerably. There is a broad consensus in Germany that it is necessary to redefine the course content and structure and put them on a theoretical basis. The article pinpoints the problems of children with special needs, and especially of those whose family language is not German. Despite some positive developments in German ECCE little progress has been made with regard to effectively implementing the conceptual unity of education, care and upbringing.  相似文献   

德国大学的制度结构     

鲁道夫·施迪希伟  刘子瑜 《北京大学教育评论》2010,8(3):40-50,188

本文以组织进化理论的眼光审视了德国大学近三百年的发展历程,从中抽象出德国大学作为一种制度的基本规则,并运用横向与纵向的比较和梳理勾勒出德国大学历史发展背后的脉络.本文指出,德国大学的制度核心,即对德国大学系统构成起到基础性作用的制度规则主要是:国家与大学紧密联系,却又不损害大学本身的学术自由;德国大学在知识上具有极大的包容性,并倡导研究与教学相统一;最后,在德国分权化的政治背景下,大学之间的自由竞争推动了德国高等教育的发展.  相似文献   

政策和实践的困境(下)     

大卫·K·科恩  苏珊·L·莫菲特  西蒙娜·戈尔丁 《华东师范大学学报(教育科学版)》2010,28(4):1-9

教育政策和实践总是处在困境之中,这是困扰政策制定者和实践者的问题.本文着力从教育政策和实践所面临的困境、如何处理困境的角度,重新审视政策和实践两者的关系,并从政策目标、政策工具和实践中的能力三方面对其展开论述,以期在冲突的基础上促进教育政策和实践间的融合.  相似文献   

Science Teachers’ Professional Development and Changes in Science Practical Assessment Practices: What are the Issues?   总被引：1，自引：0，他引：1  

Phillip A. Towndrow  Aik-Ling Tan  Benny H. W. Yung  Libby Cohen 《Research in Science Education》2010,40(2):117-132

This paper considers the circumstances under which science teachers can respond positively and productively to educational policy reforms in the area of science practical assessment. To understand what might be involved in linking science teachers’ assessment capacities and their professional development, we present illustrative data from recent research studies conducted in Singapore and Hong Kong showing contrasting approaches taken in the implementation of reforms in science practical assessment. In Singapore, teachers worked together to select, discuss, clarify and refine their practices as they made decisions about what to teach and assess. In Hong Kong, teachers took a critical stance towards the new policy and learnt from their own experiences in order to build their confidence. With the same policy initiative, one group of teachers focused more on the technicalities of complying with requirements imposed on them while in the other group had their professional consciousness of what they thought was best for their students provoked so that their practices would be transformed. In an attempt to draw lessons for other contexts in supporting the implementation of assessment policy reforms through professional development work, we identify and discuss a range of factors in science teachers’ professional development that arise once in situ professional development work has started. Overall, our intent in this article is to recast assessment reform as a driver or pivot in teachers’ professional development and learning. To do this it is necessary, we argue, to afford teachers’ experiences and the processes involved in learning from them greater emphasis in order to ensure the continuance of innovation in the assessment of laboratory-based work.  相似文献