A review of tennis racket performance parameters

The application of advanced engineering to tennis racket design has influenced the nature of the sport. As a result, the International Tennis Federation has established rules to limit performance, with the aim of protecting the nature of the game. This paper illustrates how changes to the racket affect the player-racket system. The review integrates engineering and biomechanical issues related to tennis racket performance, covering the biomechanical characteristics of tennis strokes, tennis racket performance, the effect of racket parameters on ball rebound and biomechanical interactions. Racket properties influence the rebound of the ball. Ball rebound speed increases with frame stiffness and as string tension decreases. Reducing inter-string contacting forces increases rebound topspin. Historical trends and predictive modelling indicate swingweights of around 0.030–0.035 kg/m² are best for high ball speed and accuracy. To fully understand the effect of their design changes, engineers should use impact conditions in their experiments, or models, which reflect those of actual tennis strokes. Sports engineers, therefore, benefit from working closely with biomechanists to ensure realistic impact conditions.     

Floating collection in an academic library: An audacious experiment that succeeded

Can a floating collection thrive in a large multicampus academic research library? Floating collections have been successful in public libraries for some time, but it is uncommon for academic libraries and unheard of for a large academic library system. This article will discuss the investigation into the feasibility of a floating collection at Penn State University Libraries, its implementation, and continuation for a period covering 2009 through 2015. Attaining the floating collection, limited to monographs in the general stacks of campus libraries, proved to be easier to implement than imagined and resulted in unintended benefits as well as some surprises.     

如何开展家长培训

残障儿童的父母．是孩子一生最好的教育者，因为他们在孩子成长的过程中无私奉献，恪尽责任。对那些有残障儿童的家庭而言．“知识就是力量”这句话就是真理。这些家长需要掌握关于残障症状的特点、教育治疗方案和策略等信息，以提升日常生活质量。家长们也想知道什么样的服务最适合孩子．如何获得这些服务．如何定位家长角色以确保孩子的进步．[第一段]     

The impact of standards-based assessment on knowledge for history education in New Zealand

This paper examines how a standards-based form of assessment in operation in New Zealand has impacted upon the knowledge taught to secondary history students. The segmentation of history into assessable components along with assessment mechanisms which encourage the reduction in the number of standards being attempted has impacted upon both the breadth and range of historical content in history programmes. The reduction in knowledge is problematic as it diminishes learners’ opportunities to draw connections between inter-related historical concepts from a wider knowledge base. Social realists have raised concerns about the reduced focus on knowledge in education and its effects in restricting students’ development of conceptual knowledge which enables higher order, more abstract thinking. Experiences of standards-based assessment for history in New Zealand are indicative of this reductive phenomenon. In a culture of accountability, standards-based assessment, as enacted in New Zealand, may impede delivery of critical knowledge.     

Distance education plans: Course planning for online adult learners

TechTrends - There can be an untethered excitement connected with ever-expanding technologies and the vastness of educational opportunities that online learning generates. Yet, these new and...     

Latent Profiles of Reading and Language and Their Association With Standardized Reading Outcomes in Kindergarten Through Tenth Grade

The objective of this study was to determine the latent profiles of reading and language skills that characterized 7,752 students in kindergarten through tenth grade and to relate the profiles to norm-referenced reading outcomes. Reading and language skills were assessed with a computer-adaptive assessment administered in the middle of the year and reading outcome measures were administered at the end of the year. Three measures of reading comprehension were administered in third through tenth grades to create a latent variable. Latent profile analysis (LPA) was conducted on the reading and language measures and related to reading outcomes in multiple regression analyses. Within-grade multiple regressions were subjected to a linear step-up correction to guard against false-discovery rate. LPA results revealed five to six profiles in the elementary grades and three in the secondary grades that were strongly related to standardized reading outcomes, with average absolute between-profile effect sizes ranging from 1.10 to 2.53. The profiles in the secondary grades followed a high, medium, and low pattern. Profiles in the elementary grades revealed more heterogeneity, suggestive of strategies for differentiating instruction.     

Differential recognition of children's cultural practices in middle primary literacy classrooms

This paper argues that teachers' recognition of children's cultural practices is an important positive step in helping socio‐economically disadvantaged children engage with school literacies. Based on 21 longitudinal case studies of children's literacy development over a 3‐year period, the authors demonstrate that when children's knowledges and practices assembled in home and community spheres are treated as valuable material for school learning, children are more likely to invest in the work of acquiring school literacies. However, they also show that while some children benefit greatly from being allowed to draw on their knowledge of popular culture, sports and the outdoors, other children's interests may be ignored or excluded. Some differences in teachers' valuing of home and community cultures appeared to relate to gender dimensions.     

Bullying and the Unique Socioemotional Needs of Gifted and Talented Early Adolescents: Veteran Teacher Perspectives and Practices

Much is written at the elementary school level concerning bullying and the socioemotional needs of gifted and talented (GT) students; however, in the last 10 years, little qualitative research exists concerning the early adolescent GT age group. In the social environment of classroom life, early and current research indicates that many of these students experience neurotic perfectionism, overexciteabilities (OEs), developmental asynchrony, and bullying. The formation of autonomous classes (GT-only classes) has afforded some hope concerning the amelioration of such problems; nevertheless, in this study, detailed evidence of classroom bullying in the form of social ostracism and teasing has been found with this GT age group. If left unchecked, psychological autopsies have shown these students suffering emotional difficulties and even committing suicide as a result of school and classroom torment. With such potential for classroom bullying problems, few studies address what veteran teachers of early adolescent GT students do to keep students psychologically safe. Within the social milieu of classroom life, and in comparison to research standards, this study explores three efficacious teacher perspectives and practices.