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161.
We analyze the advent and development of eight scientific fields from their inception to maturity and map the evolution of their networks of collaboration over time, measured in terms of co-authorship of scientific papers. We show that as a field develops it undergoes a topological transition in its collaboration structure between a small disconnected graph to a much larger network where a giant connected component of collaboration appears. As a result, the number of edges and nodes in the largest component undergoes a transition between a small fraction of the total to a majority of all occurrences. These results relate to many qualitative observations of the evolution of technology and discussions of the “structure of scientific revolutions”. We analyze this qualitative change in network topology in terms of several quantitative graph theoretical measures, such as density, diameter, and relative size of the network's largest component.To analyze examples of scientific discovery we built databases of scientific publications based on keyword and citation searches, for eight fields, spanning experimental and theoretical science, across areas as diverse as physics, biomedical sciences, and materials science. Each of the databases was vetted by field experts and is the result of a bibliometric search constructed to maximize coverage, while minimizing the occurrence of spurious records. In this way we built databases of publications and authors for superstring theory, cosmic strings and other topological defects, cosmological inflation, carbon nanotubes, quantum computing and computation, prions and scrapie, and H5N1 influenza. We also built a database for a classical example of “pathological” science, namely cold fusion. All these fields also vary in size and in their temporal patterns of development, with some showing explosive growth from an original identifiable discovery (e.g. carbon nanotubes) while others are characterized by a slow process of development (e.g. quantum computers and computation).We show that regardless of the detailed nature of their developmental paths, the process of scientific discovery and the rearrangement of the collaboration structure of emergent fields is characterized by a number of universal features, suggesting that the process of discovery and initial formation of a scientific field, characterized by the moments of discovery, invention and subsequent transition into “normal science” may be understood in general terms, as a process of cognitive and social unification out of many initially separate efforts. Pathological fields, seemingly, never undergo this transition, despite hundreds of publications and the involvement of many authors. 相似文献
162.
Brian E. Vaughn Nana Shin Mina Kim Gabrielle Coppola Lisa Krzysik António J. Santos Inês Peceguina João R. Daniel Manuela Veríssimo Anthon DeVries Eric Elphick Xiomara Ballentina Kelly K. Bost Wanda Y. Newell Ellaine B. Miller J. Blake Snider Byran Korth 《Child development》2009,80(6):1775-1796
The generality of a multilevel factorial model of social competence (SC) for preschool children was tested in a 5‐group, multinational sample (N = 1,540) using confirmatory factor analysis. The model fits the observed data well, and tests constraining paths for measured variables to their respective first‐order factors across samples also fit well. Equivalence of measurement models was found at sample and sex within‐sample levels but not for age within sample. In 2 groups, teachers’ ratings were examined as correlates of SC indicators. Composites of SC indicators were significantly associated with both positive and negative child attributes from the teachers’ ratings. The findings contribute to understanding of both methodological and substantive issues concerning SC in young children. 相似文献
163.
Maria Inês Mafra Goulart Wolff-Michael Roth 《Cultural Studies of Science Education》2010,5(3):533-562
In this study we investigate how 5-year-old children in Brazil and their teachers collectively design science curriculum.
More specifically, we develop an agency|structure dialectic as a framework to describe this collective praxis in which science
curriculum may emerge as the result of children–teacher transactions rather than as a result of being predetermined and controlled
by the latter. We draw on a cultural-historical approach and on the theory of structure and agency to analyze the events showing
the complexity of the activity inside a classroom of very young children by science education standards. Data were collected
in the context of a science unit in an early-childhood education program in Belo Horizonte. Our study suggests that (a) throughout
the movement of agency|passivity || schema|resources one can observe participative thinking, a form of collective consciousness
that arises in and from lived experience; (b) learning is a process in which a group is invested in searching for solutions
while they create schemas and rearrange resources to evolve a new structure; and (c) the emergent curriculum is a powerful
form of praxis that develops children’s participation from early childhood on. 相似文献
164.
The study reported here examined grade 2–4 children’s sensitivity to the consistency in the spelling of roots in related words.
We build on earlier research by attempting to quantify the extent that children’s spellings of both inflected and derived
forms accord with this principle. We contrasted children’s accuracy and consistency in spelling the root form (e.g., rock) with that of its spelling in related inflected and derived forms (e.g., rocks and rocky), as well as unrelated control forms (e.g., rocket). Across grades 2–4, children’s spellings accorded with the root consistency principle to the same extent for inflected and
derived forms. Nevertheless, it was not until grade 4 that spellings maximally reflected the principle. These results are
discussed in terms of how children’s spelling might come to reflect the root consistency principle that guides spelling in
English. 相似文献
165.
Marie-Hélène Chayer Thérèse Bouffard 《European Journal of Psychology of Education - EJPE》2010,25(1):125-140
The first objective of this study was to examine the presence of the impostor phenomenon (IP) among 740 students aged 10 to
12 years old. The second objective was twofold: (1) to examine the link between the impostor feelings and the propensity to
use social comparison and (2) to examine whether this feeling is related to the processes of identification with versus contrast
to others who are either doing better or worse than oneself. Results showed that, although generally of low intensity, the
impostor feelings are indeed present in late elementary school children. A positive link between the impostor feelings and
the propensity to use social comparison was also observed. It also appeared that, more than for others, children who feel
like impostors were likely to differentiate themselves from their more capable peers while identifying themselves with less
capable peers. The discussion focuses on the presence of the IP in late elementary children and on how the upward contrast
and the downward identification may contribute to its development and maintenance. 相似文献
166.
Victoria Reyes-García Eric Kightley Isabel Ruiz-Mallén Nuria Fuentes-Peláez Katie Demps Tomás Huanca Maria Ruth Martínez-Rodríguez 《International Journal of Educational Development》2010
Schooling and the knowledge acquired at school have been considered both a cause of loss of indigenous knowledge (because it opens pathways to the non-indigenous world and worldviews) and a potential remedy to its demise (if educational curricula is aligned with indigenous realities by giving instruction in local languages and incorporating local knowledge in school content). We test the association between academic and local environmental knowledge using data from a society of forager-horticulturalists in the Bolivian Amazon who were exposed to a partially contextualized school curriculum. We found that although schooling and academic knowledge bear a negative association with local knowledge the magnitude is low, probably because schooling was partially contextualized. Contextualized learning might help avoid that the provision of universal education comes at the cost of humanity's cultural diversity. 相似文献
167.
Thomas?ArnoldEmail authorView authors OrcID profile Matthias?Scheutz 《Ethics and Information Technology》2018,20(1):59-69
As a way to address both ominous and ordinary threats of artificial intelligence (AI), researchers have started proposing ways to stop an AI system before it has a chance to escape outside control and cause harm. A so-called “big red button” would enable human operators to interrupt or divert a system while preventing the system from learning that such an intervention is a threat. Though an emergency button for AI seems to make intuitive sense, that approach ultimately concentrates on the point when a system has already “gone rogue” and seeks to obstruct interference. A better approach would be to make ongoing self-evaluation and testing an integral part of a system’s operation, diagnose how the system is in error and to prevent chaos and risk before they start. In this paper, we describe the demands that recent big red button proposals have not addressed, and we offer a preliminary model of an approach that could better meet them. We argue for an ethical core (EC) that consists of a scenario-generation mechanism and a simulation environment that are used to test a system’s decisions in simulated worlds, rather than the real world. This EC would be kept opaque to the system itself: through careful design of memory and the character of the scenario, the system’s algorithms would be prevented from learning about its operation and its function, and ultimately its presence. By monitoring and checking for deviant behavior, we conclude, a continual testing approach will be far more effective, responsive, and vigilant toward a system’s learning and action in the world than an emergency button which one might not get to push in time. 相似文献
168.
Daniel Aragonés Alexander Eekhoff Fabian Horst Wolfgang Immanuel Schöllhorn 《Journal of sports sciences》2018,36(11):1296-1304
Training consisting of numerous repetitions performed as closely as possible to ideal techniques is common in sports and every-day tasks. Little is known about fatigue-related technique changes that emerge at different timescales when repeating complex actions such as a karate front kick. Accordingly, 15 karatekas performed 600 kicks (1 pre-block and 9 blocks). The pre-block comprised 6 kicks (3 with each leg) at maximum intensity (K-100%). Each block comprised 60 kicks (10 with each leg) at 80% of their self-perceived maximum intensity (K-80%) plus 6 K-100%. In between blocks, the participants rested for 90 seconds. Right leg kinematics (peak joint angles, peak joint angular velocities, peak joint linear resultant velocities, and time of occurrence of peaks) and kick duration corresponding to the K-80% were measured resulting in numerous variations with fatigue. At the timescale of tens of seconds, the changes involved variables that were related to velocity of execution (slowed down), while variables related to movement form were hardly affected. At the timescale of tens of minutes, the opposite results were observed. These findings challenge the long-standing rationale underlying repetitive training, suggesting instead that such involuntary variations in technique might play a crucial role in motor skill training 相似文献
169.
Juan J. Pulido David Sánchez-Oliva Francisco M. Leo Jorge Sánchez-Cano Tomás García-Calvo 《Measurement in physical education and exercise science》2018,22(1):25-37
Purpose: The objectives were to develop and validate the Coaches’ Interpersonal Style Questionnaire. The Coaches’ Interpersonal Style Questionnaire analyzes the interpersonal style adopted by coaches when implementing their strategy of supporting or thwarting athletes’ basic psychological needs. Method: In Study 1, an exploratory factor analysis was performed with 265 Spanish male athletes, between 11- and 17-years-old, to confirm the internal structure of the questionnaire. Study 2 was conducted with 430 athletes, also between 11- and 17-years-old. Both confirmatory factor analysis and exploratory structural equation modeling were used to test a set of alternative models to find the best measurement model. Results: The hierarchical exploratory structural equation modeling model showed the best fit to the data and acceptable standardized factor loadings. Concurrent validity was revealed through correlational analysis of the basic psychological need satisfaction and frustration. Conclusion: This study provides a multi-dimensional questionnaire to assess coaches’ interpersonal style perceived by athletes. 相似文献
170.
Aurélio Faria Ronaldo Gabriel Helena Moreira Tanya Camacho Rui Brás Massimiliano Ditroilo 《European Journal of Sport Science》2018,18(4):483-490
Purpose: The main purpose of this study was to investigate the influence of fatigue on musculoarticular stiffness (MAS) of the ankle joint across sexes. Methods: Twenty-seven males and 26 females participated in the study. After baseline assessment of MAS and related variables, localised fatigue was induced in triceps surae using the standing heel-rise test during which the subjects were instructed to lift and drop the heel at a frequency of 0.5?Hz. When subjects were unable to continue due to exhaustion the test was terminated and another MAS test was performed soon after. Results: Significant higher triceps surae MAS was found in men compared to women (p?.01). MAS decreased (p?.01) between pre- and post-fatigue on average from 18.0 to 17.0?KN?m?1 and from 14.5 to 13.9?KN?m?1 in men and women, respectively. Percentage changes revealed, however, that in relative terms the changes in all the variables evaluated were similar (p?>?.01) between sexes, with MAS less than 5%. Conclusion: Despite the sex-related differences at baseline, fatigue seems to affect biomechanical properties of the ankle joint similarly in men and women. 相似文献