The penalty throw in water polo: A cinematographic analysis

Three‐dimensional (3‐D) high‐speed cinematography was used to record the penalty throw in water polo by six elite male (M) and six elite female (F) players. The direct linear transformation technique (DLT) was used in the 3‐D space reconstruction from 2‐D images recorded via laterally placed phase‐locked cameras operating at 200 Hz. Five of the twelve subjects lifted the ball from underneath at the start of the throw whilst the remaining subjects opted for a rotation lift. As the ball was brought behind the head the females used very little hip and shoulder rotation compared to the male players so that four of the six female subjects were square on to the target at the rear point. At the completion of the backswing the wrist was flexed to a similar angle (M‐162°; F‐158°); the elbow angle showed significantly greater flexion for females (85°) than males (107°).

During the forward swing, from rear point to release, the wrist joint of the female players flexed from a rear point angle of 158° to 148° at release. The wrist movement for male subjects was different from the females in that it flexed from 162° to 147°, 0.10 s prior to release and then extended to 159° at palmar release before again flexing to 156° at release. The amount of elbow extension during the forward swing was 48° for both groups; however, the females actually released the ball with the forearm vertical (89°) compared to the male forearm angle of 78°. Maximum angular velocity of the wrist and elbow occurred at release for 9 of the 12 subjects. Both the wrist and elbow joints (F‐148°; M‐156° at wrist and F‐126°; M‐148° at elbow) demonstrated greater flexion at release in female subjects, compared with males. Maximum linear endpoint velocities for the forearm and hand segments occurred at ball release resulting in mean ball velocities of 19.1 m s ^‐1 and 14.7 m s^{‐ 1} for male and female subjects respectively.     

Predicting Physical Activity Among Children: Investigating Interaction Effects in the Theory of Planned Behavior

ABSTRACT

Purpose: The theory of planned behavior (TPB) has been criticized for not including interactions between the variables assumed to predict behavior. This study sought to test how TPB variables interact to predict physical activity (PA) in children. Method: Four hundred thirty-eight children (M_age = 8.6 years, SD = 1.6 years) completed a TPB questionnaire and a PA questionnaire at Time 1. The PA measure was repeated 2 months later. Path analyses were performed to test the hypothesized model including interaction terms between TPB variables. Simple slopes analyses were also carried out to examine the statistically significant interaction terms. Results: Path analyses confirmed the classical hypotheses of TPB (R² for intentions = .39, R² for PA = .12) and also demonstrated only statistically significant Attitudes × Perceived Behavioral Control and Subjective Norms × Attitudes interactions (R² change for intentions = .01, p = .009). Simple slopes analyses revealed that the strength of the association between perceived behavioral control and intentions was only statistically significantly higher (t = 2.18, p = .05, d = 0.34, 95% CI [0.03, 0.65]) when attitudes were high compared with when attitudes were low. The link between attitudes and intentions was only statistically significant at a low level of subjective norms but not at a high level. Conclusion: The integration of interaction effects between TPB variables did not increase for the variance of PA explained by the model. More research appears to be necessary to explore how the TPB could be augmented to better predict PA in children.     

The Role of Struggle in Pre-Service Elementary Teachers’ Experiences as Students and Approaches to Facilitating Science Learning

Science education researchers are concerned with preparing pre-service elementary teachers (PSETs) to teach in ways that support students to learn science in a meaningful way. Preparing elementary teachers to teach science is complicated given that they tend to be generalists and may not have the same experience with science as secondary teachers. During an elementary science methods course, we explored PSETs?? perspectives on the teaching and learning of science via a case study that included four PSETs. Using Frykholm??s (Journal of Curriculum and Supervision 19:125?C149, 2004) framework of ??educative?? and ??debilitating?? discomfort, we examined PSETs?? approaches to their own science learning and their approaches to science teaching. A theme apparent in PSETs?? perspectives was struggle. We described ways in which struggle was either educative or debilitating for PSETs, both in terms of their own learning and the ways in which they approached teaching. Some PSETs who struggled in their own learning developed learning experiences to engage their students in reform-based science teaching, while some PSETs developed learning experiences that prevented their students from experiencing any sort of struggle in their learning process. The ways in which these students dealt with their own learning struggles mirrored the ways in which they dealt with their struggles to become teachers of reform-based science instruction. Helping PSETs to deal with their feelings of discomfort with science content or ideas about the nature of science learning and teaching promoted by reform documents may be a key issue in developing their willingness to become facilitators of meaningful science learning.     

Does Student Philanthropy Work? A Study of Long-term Effects of the “Learning by Giving” Approach

Student philanthropy is a teaching strategy designed to engage students actively in the curriculum, increase awareness of social needs and nonprofit organizations, and teach grant-writing and grant-making skills. This is the first study to examine long-term effects of student philanthropy by surveying alumni years after their experience with this teaching strategy. A majority of respondents indicated that student philanthropy had a positive effect on their awareness, learning, beliefs, and intentions. Further, 86% of student philanthropy alumni had recently made charitable contributions, 71% reported volunteering, and 15% served on nonprofit boards – all of which are much higher than the national averages for these behaviors.     

Knowledge about Pronouns: A Developmental Study Using a Truth-Value Judgment Task

In this article we report on children's (3 to 7 years) and adults'knowledge of grammatical and pragmatic principles of pronoun interpretation. A controlled version of a truth-value judgment task involving sentence-picture matching revealed (i) a continuous role of structure-dependence in pronoun interpretation across the full age range tested; (ii) a significant effect of pronoun directionality (although its exact form changed with development ); (iii) and a growth into adulthood of pragmatic bias in pronoun interpretation. The results contribute to current debates regarding the continuity of principles of "Universal Grammar" and also to issues of research methodology in first language acquisition.     

Summer Scientific Research for Teachers: The Experience and its Effect

Journal of Science Teacher Education -     

An investigation of increased rates of autism in U.S. public schools

This study is intended to enhance our understanding of the dramatic increase in autism prevalence rates across the United States. A robust national and multistate sample of children and youth (5–22 years of age) was gathered and analyzed, using visual and statistical analysis of autism eligibility over a 15‐ to 17‐year period. Although the impact of environmental or genetic influences cannot be entirely ruled out, we identified significant shifts in eligibility trends that substantially contribute to the remarkable increase in autism prevalence. Assessment procedures and criteria for autism have sustained an indelible influence from this diagnostic migration, which has had a lasting impact on public schools. We use this information to provide meaningful implications for practicing psychology in the schools.     

Why Are Children So Distractible? Development of Attention and Motor Control From Childhood to Adulthood

Distractibility is the propensity to behaviorally react to irrelevant information. Although children are more distractible the younger they are, the precise contribution of attentional and motor components to distractibility and their developmental trajectories have not been characterized yet. We used a new behavioral paradigm to identify the developmental dynamics of components contributing to distractibility in a large cohort of French participants balanced, between age groups, in gender and socioeconomic status (N = 352; age: 6–25). Results reveal that each measure of these components, namely voluntary attention, distraction, impulsivity, and motor control, present a distinct maturational timeline. In young children, increased distractibility is mostly the result of reduced sustained attention capacities and enhanced distraction, whereas in teenagers, it is the result of decreased motor control and increased impulsivity.     

Fostering Self-Reflection and Meaningful Learning: Earth Science Professional Development for Middle School Science Teachers

This paper describes the analysis of teachers’ journal reflections during an inquiry-based professional development program. As a part of their learning experience, participants reflected on what they learned and how they learned. Progress of subject matter and pedagogical content knowledge was assessed though surveys and pre- and posttests. We found that teachers have difficulties reflecting on their learning and posing meaningful questions. The teachers who could describe how they reasoned from evidence to understand a concept had the highest learning gains. In contrast those teachers who seldom or never described learning a concept by reasoning from evidence showed the smallest learning gains. This analysis suggests that learning to reflect on one’s learning should be an integral part of teachers’ professional development experiences.     

Head Start in Transition

This article explores the history of Head Start, the federal early education program for economically disadvantaged preschool children in the United States, as a way of understanding what it means to talk about change in the late twentieth century. The history of Head Start has been a story of administrative changes and improvement and accountability initiatives in the realm of public policy, a ominant narrative of progress and rational planning that is consonant with a large, centralized governance structure. In an effort to create another way of conceiving of the organization, we first examine shifting definitions and conflicting interpretations of parental involvement and staff development within the program to reveal some of the tensions inherent in all human endeavors. We then draw on interviews with women who work in and are served by Head Start to show how needs and resources vary and how policy mandates can have differential—and unintended—effects. In the conclusion, we suggest, following Toulmin (1990), that the certainty and stability that has characterized public policy since the Enlightment must now be tempered with a postmodern recognition of change, complexity, and variability. Rather than one history, we see many histories. Instead of one approach, we see value in tailoring improvement initiatives to the needs of families and staff in specific circumstances.