Effect of Practice on True Score and Intra-Individual Variability for Reaction and Movement Times for Simple and Complex Movements

Abstract

The effect of practice on individual differences and intra-individual variability in reaction and movement times were studied for simple and complex, discrete, motor tasks. Changes with practice for intertrial correlations of adjacent trials and the effects of an increasing number of interpolated trials on intertrial correlations were also observed. For both tasks and for both reaction and movement times, the intra-individual variability decreased with practice. The true score variability for reaction time on both tasks and for movement time on the simple task shows little change with practice. On the complex task, true score variability for movement time decreases with practice. For movement time, adjacent trial correlations increase during the early practice trials then remain stable. For reaction time adjacent trial correlations increase throughout practice. Remoteness effects on intertrial correlations were found for both movement and reaction times for both tasks.     

Frequency Distributions and Standards of Anthropometric and Physical Performance Measures for College Women

Abstract

Frequency distributions of the records of a random selection of 200 college women in a nonmajor required program on anthropometric and physical performance measures commonly employed in physical education were compared with best-fitting normal curves for the same data. A table of random numbers was used to secure the sample. A percentile table for the various measurements was constructed. It was concluded that various measurements commonly employed by physical educators give a non-normal distribution. Hence, the obtained distribution as found on various measurements in this study does not warrant treating these data as normal.     

基于专利的北京新一代信息技术产业SWOT分析

本文以北京新一代信息技术产业为对象,在传统专利地图的基础上,结合专利授权率、研发能力、专利技术价值、技术机会、技术优势等分析方法,采用国内专利和国际专利数据,对北京发展新一代信息技术产业的优势、劣势、机会、威胁进行了定量与微观层面的分析,在与国内外地区专利情况的对比中明确了发展方向。在此基础上提出了北京发展新一代新兴技术产业的对策。研究结果表明,上述思路和分析方法对于分析我国战略性新兴产业现状与对策也具有指导意义。     

历史与社会新课程教学·让学生心灵开放

新课程所蕴含的先进的教育理念,已经成为当前素质教育改革的重点,但是教师怎样才能顺应时代发展的潮流来构建符合新课程教学理念的创新教学模式？而这一问题,正是我们广大教师在新课程改革中需要思考和探索的实际问题。     

Current studies on two separate topics: breastfeeding postpartum length of hospital stay

IN THIS COLUMN, THE AUTHOR EXAMINES RECENT RESEARCH ON TWO SEPARATE TOPICS: 1) breastfeeding; 2) postpartum length of hospital stay. Recent studies suggest long-term effects of breastfeeding that benefit both mother and infant. Benefits include a reduced risk of breast cancer in breastfeeding mothers and a reduced level of total and LDH cholesterol in adults who were breastfed as infants. Infants of mothers with maternal asthma had lower rates of asthma if the mother breastfed. In a study of women in the United States who planned to breastfeed, those mothers who breastfed exclusively and planned to breastfeed more than three months were more likely to achieve their goals than mothers who planned to combine breast and human-milk substitute feeds and to breastfeed less than three months.In a Canadian study, shortened postpartum stays led to increased re-admission to hospital for mothers with cesarean births. In contrast, in a Massachusetts study, shortened postpartum stays did not lead to an increase in infant visits for urgent care. However, the Massachusetts study did not reflect a decrease in maternity-related costs associated with shortened length of postpartum stay.     

Critical Approaches to Lifelong Education

This paper argues that contemporary interest in lifelong learning can be seen as an artefact of the market. It points out how the attractive vocabulary associated with personal development and empowerment often masks other economic and social purposes. Bearing in mind the social function of education, the author compares the strategies for the promotion of lifelong learning designed for those in "included social categories" with the policies designed for those in marginal and excluded positions. It concludes by challenging its own position by citing positive learner experience in each case.     

细小病毒MPV—Q株理化特性及其致病性的研究

细小病毒ＭＰＶ—Ｑ株是从患病雏番鸭体内分离的一种致病性病毒。电镜及理化特性检查表明该株病毒属细小病毒，圆形无囊膜，直径在２２—２４ｕｍ、对乙醚、胰蛋白酶、酸不敏感，对红细胞无凝集现象，对鸡、丽佳鸡、北京鸭、鹅无致病性。该病毒可引起雏番鸭发生以出血性肠炎为特征的急性败血性传染病。     

Value transfer in concurrent-schedule discriminations by pigeons

When pigeons are trained on a discrete-trial simultaneous discrimination, some of the value associated with the positive stimulus appears to transfer to the negative stimulus (Zentall & Sherburne, 1994). Pigeons preferred a negative stimulus that had been discriminated from an always-positive stimulus (S+) over a negative stimulus that had been discriminated from a sometimes-positive stimulus (S±). A very different finding (suggestive of transitivity of preference or contrast) was reported by Belke (1992). On concurrent probe tests of stimuli associated with equal variable interval (VI) schedules but originally trained in alternative concurrent pairs (one with a richer schedule, the other with a poorer schedule—VI 20 sec vs. VI 40 sec and VI 40 sec vs. VI 80 sec), the stimulus originally paired with the poorer schedule was preferred. But Belke’s results may have been obtained because the pigeons had been trained to peck the VI 40 sec paired with the poorer schedule and they had been trained not to peck the VI 40 sec paired with the richer schedule. In the present experiment, we avoided this bias by training pigeons on two concurrent schedules in which the tested stimuli both had been associated with the poorer schedule of the pair [A(VI 20 sec) vs. B(VI 80 sec) and C(VI 40 sec) vs. D(VI 80 sec)]. Evidence for value transfer was demonstrated when on probe trials pigeons preferred B over D.     

隋末骁果兵浅探

骁果兵是由隋炀帝在全国范围内招募的勇武豪侠之士组成的一支精锐部队.其最初的目的是为了征辽战争的需要,"雁门之围"之后发展成为一支完全由隋炀帝控制的亲军部队.从骁果兵的待遇、管理及使用等方面来看,它是与原有府兵完全不同的募兵."江都之变"之时,江都的主要军事力量是骁果兵.骁果的发展是隋炀帝加强中央集权的重要措施之一.     

Attention and curiosity in museums

Two hundred and thirty-four museum visitors of all ages were observed as they entered the Object Gallery area of the Florida State Museum. Visitors were observed under conditions where objects were available for close inspection but could not be manipulated (baseline data) and later when the same objects were placed on tables and were available for visitors to touch, move, and use a variety of senses to inspect them (intervention data). Data were recorded on the sex, age, and number of subjects in these areas under each of the above conditions. The results obtained show a significant increase in the number of visitors entering this section of the museum when manipulatable objects were available. Baseline data showed that 58.5% of the people who entered the Object Gallery went into the drawer section. However, when manipulatable objects were made available this increased to 82.3%. Chi-square analysis was used to determine whether the presence of manipulatable objects in the area increased the number of people who entered the area. It did (p < 0.05). Chi-square analysis was also used to determine whether entering the drawer section depended on age or sex. It was found that more children entered the drawer section than adults (p < 0.05) and significantly more female children and female adults entered as a result of intervention (p < 0.05). At the same time, more male children than adults entered after intervention (p < 0.05) than before. These data are supported by considerable curiosity research indicating that both children and adults are attracted to novel as well as complex stimuli which can be manipulated in both formal and free-choice environments. The data also support the growing movement to hands-on exhibits in natural history museums and science centers around the country, as well as hands-on classroom activities from the perspective of their attention attracting and holding power and their curiosity evoking characteristics. Whether these positive factors also lead to increased knowledge or skill development is a question yet to be explored.