Home Computers and School Performance

This article assesses the effects of home computers on school performance, and examines inequalities in educational payoff among those children who have home computers. We find that having a home computer is associated with higher test scores in mathematics and reading, even after controlling for family income and for cultural and social capital. However, children from high socioeconomic status (SES) homes achieve larger educational gains from home computers than do lower SES children. Boys' performance advantage is larger than girls'. Ethnic minorities gain far less of a performance boost than whites. Home computing may generate another 'Sesame Street effect' whereby an innovation that held great promise for poorer children to catch up educationally with more affluent children is in practice increasing the educational gap between affluent and poor, between boys and girls, and between ethnic minorities and whites, even among those with access to the technology.     

Prior knowledge, attitude, and strategy use in an introduction to statistics course

The present study used both quantitative and qualitative methods to investigate the learning and motivational strategies used by students in a beginning-level statistics course. The research questions that guided the investigation are: (1) Do motivational variables account for unique variance in the academic performance of statistics students? (2) Do deeper-level processing strategies account for unique variance in the academic performance of statistics students? (3) Do successful students report using different motivation and learning strategies than unsuccessful students in a beginning-level statistics course?     

The effects of added mass on the biomechanics and performance of countermovement jumps

This study examined the kinetic and temporal differences between countermovement jumps (CMJs) and eccentrically loaded CMJs. A survey of 109 coaches and athlete showed that 87% of respondents regularly used jumps with added mass within training. Sixteen male and thirteen female track and field athletes from sprinting, hurdling and jumping events performed 5 bodyweight CMJs 5 jumps wearing a weighted jacket and 5 eccentrically loaded dumbbell (LDB) jumps trials in a randomised order. Peak force (PF), peak power (PP), flight time (FT), concentric time (CON-T), eccentric time (ECT), total time (TIME) and eccentric/concentric ratio (E/C-Ratio) were obtained from force plate data. Statistically significant differences (p < 0.05) with moderate to large magnitude effect sizes were found between men and women in FT, PP and PF but not in any of the temporal variables. The results indicated that the WJ decreased FT in men (↓9%) and women (↓10%) but LDB jumps had similar FT to CMJ. Overall, the results showed that LDB increased the E/C Ratio (↑50% and ↑42%) and decreased CON-T (↓37% and ↓25%) compared with WJ and CMJ respectively. LDB jumping is not recommended as a training modality as it tends to disrupt the relative timing of the jump action.     

Accelerometer and self-reported measures of sedentary behaviour and associations with adiposity in UK youth

This study used accelerometer and self-report measures of overall sedentary time (ST) and screen time behaviours to examine their respective associations with adiposity among UK youth. Participants (Year groups 5, 8, and 10; n=292, 148 girls) wore the SenseWear Armband Mini accelerometer for eight days and completed the Youth Activity Profile, an online report tool designed to estimate physical activity and ST.Stature, body mass and waist circumference were measured to classify adiposity outcomes (overweight/obese and central obesity). One-way between groups ANOVA and adjusted linear, logistic and multinomial logistic regression analyses were conducted. There was a significant main effect of age on total ST across the whole week (F(2, 289)=41.64, p≤0.001). ST increased monotonically across Year 5 (581.09±107.81 min·dˉ¹), 8 (671.96±112.59 min·dˉ¹) and 10 (725.80±115.20 min·dˉ¹), and all pairwise comparisons were significant at p≤0.001. A steep age-related gradient to mobile phone use was present (p≤0.001). ST was positively associated with adiposity outcomes independent of moderate-to-vigorous intensity physical activity (MVPA; p≤0.001). Engaging in >3 hours of video gaming daily was positively associated with central obesity (OR=2.12, p≤0.05) but not after adjustment for MVPA. Results further demonstrate the importance of reducing overall ST to maintain healthy weight status among UK youth.     

Comparison of step-by-step kinematics of resisted,assisted and unloaded 20-m sprint runs

This investigation examined step-by-step kinematics of sprint running acceleration. Using a randomised counterbalanced approach, 37 female team handball players (age 17.8 ± 1.6 years, body mass 69.6 ± 9.1 kg, height 1.74 ± 0.06 m) performed resisted, assisted and unloaded 20-m sprints within a single session. 20-m sprint times and step velocity, as well as step length, step frequency, contact and flight times of each step were evaluated for each condition with a laser gun and an infrared mat. Almost all measured parameters were altered for each step under the resisted and assisted sprint conditions (η² ≥ 0.28). The exception was step frequency, which did not differ between assisted and normal sprints. Contact time, flight time and step frequency at almost each step were different between ‘fast’ vs. ‘slow’ sub-groups (η² ≥ 0.22). Nevertheless overall both groups responded similarly to the respective sprint conditions. No significant differences in step length were observed between groups for the respective condition. It is possible that continued exposure to assisted sprinting might allow the female team-sports players studied to adapt their coordination to the ‘over-speed’ condition and increase step frequency. It is notable that step-by-step kinematics in these sprints were easy to obtain using relatively inexpensive equipment with possibilities of direct feedback.     

Electronic Learning Delivery Systems: A Selection Model

Electronic learning delivery systems discussed include satellite networks, teleconferencing, Internet/Intranet networks, desktop multimedia, electronic performance support systems (EPSS), transportable audio/video (i.e., systems relying primarily on physically transportable audio-and videotaped materials), and the electronically enhanced classroom. Selecting one of these systems can be a daunting task when all relevant issues are considered. The selection model described in this article narrows the choices to the system most likely to be instructionally, economically, and technologically appropriate. After establishing working definitions, the model suggests four stages of user activity: 1) Assessing several important overall factors, including outcomes and conditions of learning, economics, synchronicity and location, and organizational culture; 2) Rating the importance of several learning system attributes to the training project; 3) Selecting the system that most ideally supports the attributes which the user has rated as important; and finally, 4) Validating the selection by reviewing the final choice in light of first stage overall factors.     

Does exercise have a protective effect on cognitive function under hypoxia? A systematic review with meta-analysis

ObjectiveThis study aimed to examine (1) the independent effects of hypoxia on cognitive function and (2) the effects of exercise on cognition while under hypoxia.MethodsDesign: Systematic review with meta-analysis. Data sources: PubMed, Scopus, Web of Science, PsychInfo, and SPORTDiscus were searched. Eligibility criteria for selecting studies: randomized controlled trials and nonrandomized controlled studies that investigated the effects of chronic or acute exercise on cognition under hypoxia were considered (Aim 2), as were studies investigating the effects of hypoxia on cognition (Aim 1).ResultsIn total, 18 studies met our inclusionary criteria for the systematic review, and 12 studies were meta-analyzed. Exposure to hypoxia impaired attentional ability (standardized mean difference (SMD) = –0.4), executive function (SMD = –0.18), and memory function (SMD = –0.26), but not information processing (SMD = 0.27). Aggregated results indicated that performing exercise under a hypoxia setting had a significant effect on cognitive improvement (SMD = 0.3, 95% confidence interval: 0.14 – 0.45, I² = 54%, p < 0.001). Various characteristics (e.g., age, cognitive task type, exercise type, exercise intensity, training type, and hypoxia level) moderated the effects of hypoxia and exercise on cognitive function.ConclusionExercise during exposure to hypoxia improves cognitive function. This association appears to be moderated by individual and exercise/hypoxia-related characteristics.     

传播与变迁:太极拳在英国的发展历程与传播动力

通过分析与太极拳在英国传播相关的书籍、期刊、报纸以及网站等介质的文本内容,结合实地调研对太极拳在英国的传播历程以及传播与变迁的动力学因素进行研究。认为:太极拳在英国的传播过程可划分为“道教文化”启蒙阶段、“杨式太极”主导阶段、“多家流派”发展阶段;其传播变迁的动力学因素主要包括太极拳的健康和技击动力因素、中国香港的交流枢纽因素、“功夫热潮”的宣传动力因素、海外华人移民的传播动力因素、“改革开放”与“文化走出去”战略的政治动力因素等。     

The usefulness for psychoeducational evaluation of preassessment screening for sensory-motor and perceptual encoding deficits

Information-processing theory and research suggest that a careful examination of the input levels of processing is an essential prerequisite to the accurate assessment of higher levels of cognition. This paper describes a preassessment screening procedure to evaluate sensory-motor and perceptual encoding processes of children referred for psychoeducational assessment. In addition, an investigation of the diagnostic utility of the screening procedure is presented. Assessment procedures and outcomes for 18 children screened for encoding deficits were compared with those of a comparison group of 23 children whose psychoeducational evaluation at the same clinic did not include the screening procedure. Results demonstrate the potential usefulness of preassessment screening for encoding deficits to inform and supplement traditional psychometric measures of intellectual functioning.