The nature of student predictions and learning opportunities in middle school algebra

In this article, we describe how using prediction during instruction can create learning opportunities to enhance the understanding and doing of mathematics. In doing so, we characterize the nature of the predictions students made and the levels of sophistication in students’ reasoning within a middle school algebra context. In this study, when linear and exponential functions were taught, prediction questions were posed at the launch of the lessons to reflect the mathematical ideas of each lesson. Students responded in writing along with supportive reasoning individually and then discussed their predictions and rationale. A total of 395 prediction responses were coded using a dual system: sophistication of reasoning, and the mechanism students appeared to utilize to formulate their prediction response. The results indicate that using prediction provoked students to connect among mathematical ideas that they learned. It was apparent that students also visualized mathematical ideas in the problem or the possible results of the problem. These results suggest that using prediction in fact provides learning opportunities for students to engage in mathematical sense making and reasoning, which promotes students’ understanding of the mathematics that they learn.     

A deterministic model based on evidence for the associations between kinematic variables and sprint kayak performance

The aim of this narrative review was to propose a deterministic model based on a review of previous research documenting the evidence for the associations between average kayak velocity and kinematic variables in sprint kayaking. Literature was reviewed after searching electronic databases using key words ‘kayak,’ ‘biomechanics,’ ‘velocity,’ ‘kinematics,’ and ‘performance.’ Our kinematic deterministic model for sprint kayaking performance shows that the average kayak velocity is determined by kayak stroke displacement and stroke time. Stroke time had the strongest correlation with 200-m race time (r = 0.86, p < 0.001), and stroke rate (inversely proportional to stroke time) was strongly correlated with average horizontal velocity over two consecutive strokes at race pace (r = ? 0.83, p < 0.05). Increased stroke rate via decreased absolute water phase time and increased relative water phase time were indicative of more elite performance. There was no significant relationship between stroke displacement and velocity; however, a large decrease in stroke displacement may be detrimental to performance. Individual characteristics may be responsible for a paddlers’ ability to achieve and sustain a given stroke rate. Coaches should theoretically focus interventions on increasing stroke rate while maintaining stroke displacement; however this hypothesis should be confirmed with prospective studies.     

Effect of aerobic and strength training on pain tolerance,pain appraisal and mood of unfit males as a function of pain location

The purpose of this study was to examine the effect of aerobic and strength conditioning on pain tolerance, pain appraisal and mood as a function of upper and lower limb pain location. Unfit males (n=48) were randomly assigned to one of four groups: aerobic training, strength training, combined aerobic and strength training, and a ‘no training’ (control) group. The fitness regimens consisted of exercising at least three times per week for 12 weeks. Pain tolerance and appraisal and mood were ascertained before the treatment (baseline), and after 6 and 12 weeks. Statistical analyses using MANOVA indicated that the presence of aerobic training increased upper limb pain tolerance but was also linked to a more severe pain appraisal compared with the absence of aerobic training. Aerobic work also improved vigour while decreasing fatigue, tension and depression. Strength training had no influence on pain tolerance and positive mood states, but increased depression. Lower limb pain tolerance was unaffected by the treatments.     

Enrollment in Physical Education Is Associated With Overall Physical Activity in Adolescent Girls

Little is known about population-level contributions of school physical education to overall physical activity (PA) in youth. Because PA levels are lower in girls than boys, it is particularly important that the effects of PE programs in adolescent girls be understood. Thus, the purpose of this study was to determine the association of enrollment in physical education and overall physical activity participation in adolescent girls. A measurement protocol was administered to cross-sectional samples of 8th-, 9th-, and 12th-grade girls participating in a school-based PA intervention study (1998–2003). PA was assessed with the 3-Day Physical Activity Recall. Three-way analyses of variance were performed to compare groups formed on the basis of physical education enrollment. For each grade group of girls, those who were enrolled in physical education reported more moderate-to-vigorous PA and more vigorous PA than nonenrolled girls. When activity in physical education classes was deleted, 8th-and 9th-grade physical education enrollees were not more active than nonenrollees; however, 12th-grade physical education enrollees remained more active than nonenrollees. Girls who were enrolled in physical education were more physically active than nonenrolled girls in all three grade levels. These findings suggest that expanded enrollment in physical education may increase American adolescent girls' PA level.