Children's Early Decontextualized Talk Predicts Academic Language Proficiency in Midadolescence

This study examines whether children's decontextualized talk—talk about nonpresent events, explanations, or pretend—at 30 months predicts seventh-grade academic language proficiency (age 12). Academic language (AL) refers to the language of school texts. AL proficiency has been identified as an important predictor of adolescent text comprehension. Yet research on precursors to AL proficiency is scarce. Child decontextualized talk is known to be a predictor of early discourse development, but its relation to later language outcomes remains unclear. Forty-two children and their caregivers participated in this study. The proportion of child talk that was decontextualized emerged as a significant predictor of seventh-grade AL proficiency, even after controlling for socioeconomic status, parent decontextualized talk, child total words, child vocabulary, and child syntactic comprehension.     

Getting What You Pay For: Children's Use of Market Norms to Regulate Exchanges

Children are sensitive to a number of considerations influencing distributions of resources, including equality, equity, and reciprocity. We tested whether children use a specific type of reciprocity norm—market norms—in which resources are distributed differentially based strictly on amount offered in return. In two studies, 195 children 5–10 years and 60 adults distributed stickers to friends offering same or different amounts of money. Overall, participants distributed more equally when offers were the same and more unequally when offers were different. Although sensitive to why friends offered different amounts of money, children increasingly incorporated market norms into their distributions with age, as the oldest children and adults distributed more to those offering more, irrespective of the reasons provided.     

A Meta-Analysis of Single-Case Research on Mathematics Word Problem-Solving Interventions for English Learners with Learning Disabilities and Mathematics Difficulties

This single-case meta-analysis is the first to provide a quantitative synthesis of the published literature on mathematics word problem-solving intervention studies for English learners with learning disabilities and mathematics difficulties. A total of ten single-subject studies were included for analysis. The current study investigated the magnitude of the effect of mathematics interventions targeting the improvement of students’ mathematics word problem-solving performance, and analyzed variables that moderated this effect. Results indicate a moderate overall effect size of 0.81 (95% CI [0.71, 0.90]) on word problem-solving performance for English learners with learning disabilities and mathematics difficulties. Moderator variables such as the implementer of the interventions, instructional focus, and word problem-solving content significantly moderated the mathematics intervention effects.     

The Rise in Single-Mother Families and Children’s Cognitive Development: Evidence From Three British Birth Cohorts

This article assessed changes in the association between single motherhood and children’s verbal cognitive ability at age-11 using data from three cohorts of British children, born in 1958 (n = 10,675), 1970 (n = 8,933) and 2000 (n = 9,989), and mediation analysis. Consistent with previous studies, direct effects were small and insignificant. For those born in 1958 and 1970 indirect effects, operating through reduced economic and parental resources, were associated with −.107-SD to −.156-SD lower attainment. Differences between the two cohorts, and by children’s age when parents separated, were insignificant. For the 2000 cohort, effect sizes for children born to single mothers did not change significantly (−.112-SD) but attenuated for children whose parents separated in early childhood (−.076-SD) or while of school age (−.054-SD).     

An Analysis of Playground Surface Injuries

Abstract

The purpose of this study was to examine the development of skill competence and tactical sophistication during a games unit conducted following the features of sport education provided by Siedentop (1994). One team of six players was followed through a 30-lesson season of “Ultimate.” Using Gréhaigne, Godbout, and Bouthier's (1997) formula for an efficiency index, together with a number of other measures of skill and tactical competence, it was determined that these students made significant improvements in selection and execution dimensions of the game. Furthermore, lower skilled students did not feel marginalized within their teams and believed they had equal opportunities for improvement. The key reasons for developing competence in this setting were the sufficient length of the season to allow for significant practice opportunities and the consistent team membership throughout season, which allowed all players to develop a sense of usefulness. This curriculum model provides one way students can develop skills through a system of game playing, provided sport education units are structured to prevent the more skillful players from dominating the games.     

Interleukin-6 and Delayed Onset Muscle Soreness Do Not Vary During the Menstrual Cycle

The purpose of this study was to determine if a difference in interleukin-6 (IL-6) and delayed onset muscles soreness (DOMS) exists in two different phases of the menstrual cycle. Nine runners performed one 75-min high-intensity interval running session during the early follicular (EF) phase and once during the midluteal (ML) phase of the menstrual cycle. Estrogen and progesterone levels were significantly reduced in the EF phase when compared to the ML phase. IL-6 levels increased from pre- to postexercise in the EF and ML phases (p < .001). There was no relationship between the IL-6 level and DOMS. The results suggest that menstruating female runners need not vary training throughout the month to reduce DOMS.     

Age Differences in Children's Ability to Model Motor Behavior

Abstract

In order to investigate the effects of modeling behavior for seven- and nine-year-old children, 30 seven-year-old and 30 nine-year-old females were randomly assigned within age level to three groups. These groups differed according to whether a model was presented at the beginning, midway, or not at all during 12 trials on the stabilometer. Both age groups were found to be similar in performance in the no model condition and, for both age groups, the beginning model condition was found to facilitate performance. However, the introduction of the model after six trials had a detrimental effect on the performance of younger children but facilitated older children's performance. These findings were interpreted in light of a likely increase in the processing capacity of nine year olds as well as an increase in the number of movement schemes that were previously stored in the older girls.     

The influence of moment of inertia on baseball/softball bat swing speed

The speed at which a player can swing a bat is central to the games of baseball and softball, determining, to a large extent, the hit speed of the ball. Experimental and analytical studies of bat swing speed were conducted with particular emphasis on the influence of bat moment of inertia on swing speed. Two distinct sets of experiments measured the swing speed of colege baseball and fast-pitch softball players using weighted rods and modified bats. The swing targets included flexible targets, balls on a tee and machine pitched balls. Internal mass alterations provided a range of inertial properties. The average measured speeds, from 22 to 31 m s⁻¹, are consistent with previous studies. Bat speed approximately correlates with the moment of inertia of the bat about a vertical axis of rotation through the batter's body, the speed generally decreasing as this moment of inertia increases. The analytical model assumes pure rotation of the batter/bat system about a vertical axis through the batter's body. Aerodynamic drag of the batter's arms and the bat is included in the model. The independent variable is bat moment of inertia about the rotation axis. There is reasonable agreement between the model and the measured speeds. Detailed differences between the two suggest the importance of additional degrees of freedom in determining swing speed.     

Determination of the swing technique characteristics and performance outcome relationship in golf driving for low handicap female golfers

Abstract

Previous studies on the kinematics of the golf swing have mainly focused on group analysis of male golfers of a wide ability range. In the present study, we investigated gross body kinematics using a novel method of analysis for golf research for a group of low handicap female golfers to provide an understanding of their swing mechanics in relation to performance. Data were collected for the drive swings of 16 golfers using a 12-camera three-dimensional motion capture system and a stereoscopic launch monitor. Analysis of covariance identified three covariates (increased pelvis–thorax differential at the top of the backswing, increased pelvis translation during the backswing, and a decrease in absolute backswing time) as determinants of the variance in clubhead speed (adjusted r ² = 0.965, P < 0.05). A significant correlation was found between left-hand grip strength and clubhead speed (r = 0.54, P < 0.05) and between handicap and clubhead speed (r = ?0.612, P < 0.05). Flexibility measures showed some correlation with clubhead speed; both sitting flexibility tests gave positive correlations (clockwise: r = 0.522, P < 0.05; counterclockwise: r = 0.711, P < 0.01). The results suggest that there is no common driver swing technique for optimal performance in low handicap female golfers, and therefore consideration should be given to individual swing characteristics in future studies.     

Parent Resource Centers: An Innovative Mechanism for Parental Involvement in School Choice Decisions

This qualitative investigation reports on the use of Parent Resource Centers (PRCs) as a mechanism for parental involvement in public school choice decisions. Interviews with parents and staff at seven PRCs in Florida revealed that PRCs employ multiple strategies to communicate choice information to parents: community-, school- and media-based outreach; outreach to hard-to-reach parents; and collaboration with other agencies. Personalized assistance and provision of choice materials are also highlighted as useful strategies. Results indicate that there is low level of awareness about school choice options among parents and thus clear and consistent communication of choice information is needed. While PRCs hold promise for increasing parental engagement in school choice, structural and systemic barriers to exercising choice decisions such as transportation and collaboration between schools and PRCs should be addressed. Methodologically, this study illustrates the power of triangulating data from parents and PRCs to illuminate our understanding of how parents make choice decisions.