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991.
Two groups of gifted adolescents solved two similar intelligence tests with differing levels of task difficulty in reverse order. Under both conditions the performance level on the less complex test was much lower, a result not observed in a control group of average intelligence. Behavioural observations revealed that the low performance of the gifted students was combined with lack of effort. This performance pattern is discussed with respect to recent postulates of achievement motivation theory, which empasize the impact not only of the achievement motive, but also of the informational value of a given task for evaluating own level of ability. It is argued that the perceived informational value of the easier test was not high enough to create an incentive for the gifted students to perform at the highest possible level  相似文献   
992.
Children’s obesity rates have increased substantially over the past several decades, due in part to unhealthy eating habits. About 75% of preschool-aged children consume fewer fruits and vegetables than recommended for health. Because children begin developing eating habits during early childhood, obesity prevention programs are increasingly targeting young children in early childhood education (ECE) settings and are involving their families in teaching about healthy eating. The purpose of this pilot study is to assess the effectiveness of a family involvement activity known as the family backpack in increasing fruit and vegetable consumption among 4- and 5-year-old children and their parents through hands-on activities that encourage them to explore and discuss fruits and vegetables at home. Forty-two families (22 experimental, 20 control) participated in the study. Families received a family backpack from their child’s ECE teacher and completed activities with their child at home during a specific week. Experimental-group backpacks contained a children’s book and three activities to encourage parent–child discussion about fruits and vegetables; control-group backpacks contained an unrelated book and activities. Children’s and parents’ fruit and vegetable consumption and frequency of serving fruits and vegetables at home were assessed using parent self-report surveys before and after completing backpack activities. Parents in the experimental group, but not the control group, reported increases in their own and their children’s fruit and vegetable consumption after completing family backpack activities. Family backpacks show promise as a tool for early childhood educators to help families reinforce and expand children’s learning and encourage healthy eating habits at home.  相似文献   
993.
Textbook vetting and evaluation process intends to ensure that the materials provided are relevant, of the required quality, suitable ad would enhance learning efficiency and effectiveness. The paper investigates the role of publishers and Tanzania Institute of Education (TIE) in the textbooks vetting and evaluation process; examines factors used to vet, evaluate and approve primary and secondary school textbooks in Tanzania and proposes Strategies that would enhance the textbook vetting, evaluation and process. The study used a mixed method research design. Respondents were selected educational publishers; MoEVT, Baraza la Kiswahili Tanzania, TIE, and Publishers Association of Tanzania. Questionnaire and semi- structured interview were used to collect data which were analysed qualitatively and quantitatively. Major findings of the study were; textbooks vetting and evaluation process is not professionally conducted although standard criteria have been established; there is not well established roles among key players involved in the vetting and evaluation process leading to conflict of interest between TIE and the publishers. The study recommends establishing an independent professional evaluation board and a well-defined timetable and effective communication among various players; enacting a book policy and adopting a limited multiple-textbook publishing system.  相似文献   
994.
Abstract

The dynamic properties of six types of tennis balls were measured using a force platform and high-speed digital video images of ball impacts on rigidly clamped tennis rackets. It was found that the coefficient of restitution reduced with velocity for impacts on a rigid surface or with a rigidly clamped tennis racket. Pressurized balls had the highest coefficient of restitution, which decreased by 20% when punctured. Pressureless balls had a coefficient of restitution approaching that of a punctured ball at high speeds. The dynamic stiffness of the ball or the ball-racket system increased with velocity and pressurized balls had the highest stiffness, which decreased by 35% when punctured. The characteristics of pressureless balls were shown to be similar to those of punctured balls at high velocity and it was found that lowering the string tension produced a smaller range of stiffness or coefficient of restitution. It was hypothesized that players might consider high ball stiffness to imply a high coefficient of restitution. Plots of coefficient of restitution versus stiffness confirmed the relationship and it was found that, generally, pressurized balls had a higher coefficient of restitution and stiffness than pressureless balls. The players might perceive these parameters through a combination of sound, vibration and perception of ball speed off the racket.  相似文献   
995.
A stochastic actor‐based model was used to investigate the origins of sex segregation by examining how similarity in sex of peers and time spent in gender‐typed activities affected affiliation network selection and how peers influenced children's (= 292; Mage = 4.3 years) activity involvement. Gender had powerful effects on interactions through direct and indirect pathways. Children selected playmates of the same sex and with similar levels of gender‐typed activities. Selection based on gender‐typed activities partially mediated selection based on sex of peers. Children influenced one another's engagement in gender‐typed activities. When mechanisms producing sex segregation were compared, the largest contributor was selection based on sex of peers; less was due to activity‐based selection and peer influence. Implications for sex segregation and gender development are discussed.  相似文献   
996.
This paper presents the results of a major investigation by questionnaire of author attitudes towards scholarly publishing, which was funded by the Publisher's Association. Altogether, the views of nearly 4,000 authors were obtained and this paper concerns just those thousand or so authors who accepted the invitation to write freely about their own personal feelings and experiences. Using QSR N6 textual analysis software, their comments were processed and themes extracted. While the rest of the questionnaire, which was formed of closed‐question, tick‐box type questions, clearly must have had some impact on their thinking, the authors had considerable latitude in regard to what they could say. The paper provides a unique opportunity to hear their views directly. The pressing topics turned out to be (in rough order of concern): the peer‐review system, copyright, journal prices, alternative business models for journal publishing, big deals, Elsevier, electronic publishing and digital journals.  相似文献   
997.
We conduct an analysis of 1835 pledges to 10 music production projects hosted on the largest Brazilian crowdfunding platform, namely the Catarse Web site, and we assess the relation between the fundraising accumulation period, the donor–entrepreneur distance and the propensity of donors to back projects. Our results suggest a significantly negative association between distance and the value of capital pledged to projects, which is consistent with the notion that the entrepreneur’s network of close contacts might play a central role in funding. Furthermore, our results contradict the idea that crowdfunding reduces the inhibiting effect of donor–entrepreneur distance. In addition, the results show that a long project exposure is associated with higher values of pledges. These results suggest practical implications for the study of crowdfunding as a financing platform. This study contributes to the literature on the use of crowdfunding as an alternative funding source in a major emerging market.  相似文献   
998.
Supplying MEDLINE services to a widely dispersed user population in the developing countries creates numerous problems not encountered by other MEDLINE centres. The inability to interact with the user complicates system promotion and makes search formulation sometimes a gamble. Nevertheless, an evaluation survey has shown high user satisfaction. Of great concern is the still inadequate solution of document delivery. Near-term objectives are the broadening of geographic coverage and the integration of search processing with supporting hard copy supply.  相似文献   
999.
1000.
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