Trajectories of Physical Discipline: Early Childhood Antecedents and Developmental Outcomes

This study examined childhood antecedents and developmental outcomes associated with trajectories of mild and harsh parental physical discipline. Interview, questionnaire, and observational data were available from 499 children followed from ages 5 to 16 and from 258 children in an independent sample followed from ages 5 to 15. Analyses indicated distinct physical discipline trajectory groups that varied in frequency of physical discipline and rate of change. In both samples, family ecological disadvantage differentiated the trajectory groups; in the first sample, early child externalizing also differentiated the groups. Controlling for early childhood externalizing, the minimal/ceasing trajectory groups were associated with the lowest levels of subsequent adolescent antisocial behavior in both samples and with parent–adolescent positive relationship quality in the second sample.     

Momentum and kinetic energy: Confusable concepts in secondary school physics

Researchers and practitioners alike express concerns about the conceptual difficulties associated with the concepts of momentum and kinetic energy currently taught in school physics. This article presents an in‐depth analysis of the treatment given to them in 44 published textbooks written for UK secondary school certificate courses. This is set against some of the more contentious issues apparent in the literature concerned with the underlying physics and pedagogical arguments about how best to help students understand. The research evolved a set of criteria which were used to scrutinize how texts explain ideas and exemplify their applications. Despite the evident merits of many textbooks, the findings suggest that incomplete explanations are surprisingly prevalent, with several fundamental issues likely to be unclear to student readers, particularly those relating to when and where conservation might apply. Confusion exists between these difficult and somewhat overlapping ideas, arguably through the neglect of constructivist considerations. The commonly emphasized mechanistic, number‐crunching approach to the analysis of simple collision problems is judged to be un‐profitable, underlining the more general point that prevailing, accepted content and pedagogy may be the source of many misunderstandings. Implications are discussed and suggestions made for alternative treatments of these deceptively complex topics. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 739–761, 2009     

Students’ everyday knowledge and experiences as resources in educational dialogues

In this article, I analyze teachers’ use of students’ everyday knowledge and experiences as resources for learning in educational dialogues. By analyzing video data of teachers’ attempts to contextualize instruction in naturalistic settings in a lower secondary school, I examine how teachers use such resources to support and guide student learning. By employing a situated approach to learning, I provide a turn-by-turn analysis of how teachers use students’ everyday knowledge as resources to socially construct knowledge when working with academic subject matter. The concepts of intercontextuality and positioning function as analytical tools that enable an analysis of the relationships between the use of everyday experiences and the social organization of participation during teachers’ instructional work. The findings show that attempts at contextualizing instruction were identified in many of the lessons. The findings also document that teachers face both challenges and opportunities when contextualizing instruction. A turn-by-turn analysis shows that the function of everyday experiences in educational dialogues depends on how such resources are mobilized, how they are brought into the conversations, as well as the roles assigned to students in the dialogues. In the article, issues contributing to the productive use of everyday resources in educational dialogues are displayed and discussed.     

Physiological Responses to Maximal Treadmill and Handweighted Exercise

Abstract

The purpose of this investigation was to compare the peak physiological responses among four protocols that employed different amounts of handweighted exercise in 16 males (aged 26.3 ± 4.1 years). The four protocols were (a) uphill treadmill running (UR; 3.36 m-s¹, 2.5% grade increase-3 min¹); (b) uphill treadmill walking while pumping 1.36kg handweights (HW) (UWHW; 1.79ms¹, 5.0% grade increase-3 min¹; (c) treadmill walking while pumping .91-kg HW (WHW; 1.79 m-s¹, 0% grade, .91kg HW increase-3 min¹); and (d) standing in place and pumping HW (SHW; arm work as described in WHW). It was hypothesized that the peak responses would be inversely proportional to the estimated muscle mass activated (i.e., UR = UWHW > WHW > SHW). Dependent variables included peak oxygen uptake (VO₂ peak), peak heart rate (HRpeak), peak ventilation (V_epeak), and peak respiratory exchange ratio (RERpeak). No differences were noted between UR and UWHW with respect to any of the dependent variables. All variables (except RERpeak) were greater (p < .01) in UR and UWHW than either WHW or SHW. RERpeak was greater (p < .01) in UR and UWHW than in WHW. VO₂peak and HRpeak were greater (p < .01) in WHW when compared to SHW. Mean VO₂peak was 97.5, 69.7, and 60% of UR for UWHW, WHW, and SHW, respectively. Therefore, walking and pumping handweights provides a maximal stimulus to the oxygen transport system.     

Physical Fitness,Self-Esteem,and Attitudes toward Physical Activity

Abstract

A total of 165 adolescent boys took measures of physical fitness, general self-esteem, and attitudes toward physical activities. High-fit compared to low-fit boys were higher in self-estimates of physical ability (P < .007) and self-reported attraction to physical activities (P < .007) but not significantly different in general self-esteem nor in reported extent of participation in voluntary physical activities. In addition significant correlations were observed between self-estimates of physical ability and attraction to physical activity, and between attraction to physical activity and extent of voluntary participation in physical activity.