Effect of the coefficient of friction of a running surface on sprint time in a sled-towing exercise

This study investigated the effect of the coefficient of friction of a running surface on an athlete's sprint time in a sled-towing exercise. The coefficients of friction of four common sports surfaces (a synthetic athletics track, a natural grass rugby pitch, a 3G football pitch, and an artificial grass hockey pitch) were determined from the force required to tow a weighted sled across the surface. Timing gates were then used to measure the 30-m sprint time for six rugby players when towing a sled of varied weight across the surfaces. There were substantial differences between the coefficients of friction for the four surfaces (μ = 0.21–0.58), and in the sled-towing exercise the athlete's 30-m sprint time increased linearly with increasing sled weight. The hockey pitch (which had the lowest coefficient of friction) produced a substantially lower rate of increase in 30-m sprint time, but there were no significant differences between the other surfaces. The results indicate that although an athlete's sprint time in a sled-towing exercise is affected by the coefficient of friction of the surface, the relationship relationship between the athlete's rate of increase in 30-m sprint time and the coefficient of friction is more complex than expected.     

Professional development to increase teacher behavior‐specific praise: A single‐case design replication

Effective classroom instruction is contingent upon successful classroom management. Unfortunately, not all teachers successfully manage classroom behavior and need in‐service professional development. In this study, we replicated a targeted professional development approach that included a brief one‐on‐one training session and emailed visual performance feedback to increase novice teachers’ use of behavior‐specific praise, an evidence‐based classroom management skill. Dependent variables collected through direct observation included teachers’ behavior‐specific praise along with average student engagement and disruptions. Four elementary teachers participated and, based on a multiple‐baseline single‐case design, we found a functional relationship between the targeted professional development and teachers’ increased use of behavior‐specific praise. However, because of variability and one teacher's limited response, effect sizes were small for behavior‐specific praise and little change was observed in student behaviors. These findings warrant further research to determine which classroom management skills affect student behaviors overall, as well as continued evaluation of this professional development model and using school‐based coaches.     

Maternal socialization of positive affect: the impact of invalidation on adolescent emotion regulation and depressive symptomatology

This study examined the relations among maternal socialization of positive affect (PA), adolescent emotion regulation (ER), and adolescent depressive symptoms. Two hundred early adolescents, 11-13 years old, provided self-reports of ER strategies and depressive symptomatology; their mothers provided self-reports of socialization responses to adolescent PA. One hundred and sixty-three mother-adolescent dyads participated in 2 interaction tasks. Adolescents whose mothers responded in an invalidating or "dampening" manner toward their PA displayed more emotionally dysregulated behaviors and reported using maladaptive ER strategies more frequently. Adolescents whose mothers dampened their PA more frequently during mother-adolescent interactions, and girls whose mothers reported invalidating their PA, reported more depressive symptoms. Adolescent use of maladaptive ER strategies mediated the association between maternal invalidation of PA and early adolescents' concurrent depressive symptoms.     

Associations between peer bullying and classroom concentration: evidence for mediation by perceived personal safety and relationship with teacher

Being bullied is associated with a psycho-social maladjustment during childhood. One hitherto largely overlooked correlate is disrupted classroom concentration. Using data collected from 364 9–11-year-old children attending seven junior schools in the UK, we tested a model in which children’s perceived safety in two contexts (classroom and playground) and their perceived relationship with their teacher were hypothesised to mediate the association between being bullied and classroom concentration. Two analytical approaches to testing multiple mediation – product of coefficients and bootstrapping – supported the model. None of the mediation effects was moderated by sex but they were by year; in all cases the mediation effect was stronger in the older children than in the younger children (but still significant among the latter). These data suggest mechanisms through which bullying might have its effects on classroom concentration. The practical and theoretical implications are discussed.     

Who benefits from student aid? The economic incidence of tax-based federal student aid

Federal benefit programs, including federal student aid, are designed to aid targeted populations. Behavioral responses to these programs may alter the incidence of their benefits, a possibility that receives less attention in the literature compared to tax incidence. I demonstrate the importance of benefit incidence analysis by showing that the intended cost reductions of tax-based federal student aid are substantially offset by institutional price increases for a sample of 4-year colleges and universities. Contrary to the goal of policymakers, I find that tax-based aid crowds out institutional aid roughly dollar-for-dollar. Unfortunately, it is not clear how institutions utilize these captured resources, so that the ultimate incidence of the programs is uncertain.     

Preparing for the Silver Tsunami: The Demand for Higher Education Among Older Adults

Over the next decade, Baby Boomers will be reaching retirement age in large numbers and the U.S. will be undergoing one of the most significant demographic shifts in its history. This demographic shift has important implications for the role of higher education as a provider of lifelong learning and for the changing composition of postsecondary institutions. Using data from the 2005 National Household Education Survey, the results of this study informs the higher education community about this emerging student market segment as a way to help us better respond to older adults?? demand for formal learning in postsecondary institutions.     

Using Spacing to Enhance Diverse Forms of Learning: Review of Recent Research and Implications for Instruction

Every day, students and instructors are faced with the decision of when to study information. The timing of study, and how it affects memory retention, has been explored for many years in research on human learning. This research has shown that performance on final tests of learning is improved if multiple study sessions are separated—i.e., “spaced” apart—in time rather than massed in immediate succession. In this article, we review research findings of the types of learning that benefit from spaced study, demonstrations of these benefits in educational settings, and recent research on the time intervals during which spaced study should occur in order to maximize memory retention. We conclude with a list of recommendations on how spacing might be incorporated into everyday instruction.