Is starting with the feet out of the water faster in backstroke swimming?     

Cecilia Nguyen  Elizabeth J. Bradshaw  David Pease  Cameron Wilson 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(2):154-165

This study aimed to determine if starting with the feet above the water (FAW) in male backstroke swimming resulted in faster start times (15-m time) than when the feet were underwater (FUW). It was hypothesised that setting higher on the wall would generate increased horizontal force and velocity, resulting in quicker starts. Twelve high-level male backstrokers performed three trials of the FAW and FUW techniques. A biomechanical swimming testing system comprising one force plate (1,000 Hz), four lateral-view (100 Hz), and five overhead (50 Hz) video cameras captured the swimmers' performance. Data for each participant's fastest trial for each technique were collated, grouped, and statistically analysed. Analysis included Wilcoxon, Spearman Rho correlation, and regression analysis. Wilcoxon results revealed a significantly faster start time for the FAW technique (p < 0.01). Peak horizontal force was significantly smaller for FAW (p = 0.02), while take-off horizontal velocity was significantly greater (p = 0.01). Regression analysis indicated take-off horizontal velocity to be a good predictor of start time for both techniques, and the horizontal displacement of the centre of mass for the FAW start.  相似文献   

A Maximal Graded Exercise Test to Accurately Predict VO2max in 18–65-Year-Old Adults     

James D. George  Danielle I. Bradshaw  Annette Hyde  Pat R. Vehrs  Ronald L. Hager  Frank G. Yanowitz 《Measurement in physical education and exercise science》2013,17(3):149-160

The purpose of this study was to develop an age-generalized regression model to predict maximal oxygen uptake (VO_2max) based on a maximal treadmill graded exercise test (GXT; George, 1996) George, J. D. 1996. Alternative approach to maximal exercise testing and VO_2max prediction in college students. Research Quarterly for Exercise and Sport, 67: 452–457. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]. Participants (N?=?100), ages 18–65 years, reached a maximal level of exertion (mean?±?standard deviation [SD]; maximal heart rate [HR_max]?=?185.2?±?12.4 beats per minute (bpm); maximal respiratory exchange ratio [RER_max]?=?1.18?±?0.05; maximal rating of perceived exertion (RPE_max)?=?19.1?±?0.7) during the GXT to assess VO_2max (mean?±?SD; 40.24?±?9.11 mL·kg^?1·min^?1). Multiple linear regression generated the following prediction equation (R?=?.94, standard error of estimate [SEE]?=?3.18 mL·kg^?1·min^?1, %SEE?=?7.9): VO_2max (mL·kg^?1·min^?1)?=?13.160?+?(3.314 × gender; females?=?0, males?=?1) ? (.131 × age) ? (.334 × body mass index (BMI))?+?(5.177 × treadmill speed; mph)?+?(1.315 × treadmill grade; %). Cross validation using predicted residual sum of squares (PRESS) statistics revealed minimal shrinkage (R_p ?=?.93 and SEE _p ?=?3.40 mL·kg^?1·min^?1); consequently, this model should provide acceptable accuracy when it is applied to independent samples of comparable adults. Standardized β-weights indicate that treadmill speed (.583) was the most effective at predicting VO_2max followed by treadmill grade (.356), age (?.197), gender (.183), and BMI (?.148). This study provides a relatively accurate regression model to predict VO_2max in relatively fit men and women, ages 18–65 years, based on maximal exercise (treadmill speed and grade), biometric (BMI), and demographic (age and gender) data.  相似文献   

A comparison of generalizability theory and many-facet Rasch measurement in an analysis of college sophomore writing     

Richard R Sudweeks  Suzanne Reeve  William S. Bradshaw 《Assessing Writing》2004,9(3):239-261

A pilot study was conducted to evaluate and improve the rating procedure proposed for use in a research effort designed to assess the essay writing ability of college sophomores.Generalizability theory and the Many-Facet Rasch Model were each used to (a) estimate potential sources of error in the rating, (b) to obtain reliability estimates, and (c) to make recommendations for improving the rating process. Variance due to Task (writing prompt) and the Person-by-Task interaction were high while the variance attributable to Raters and Occasion was low. Twenty-two percent of the variability in the ratings was unexplained. The common and unique features of generalizability theory and the Many-Facet Rasch Model are described, and the advantages and disadvantages of each are discussed.  相似文献   

Reflecting on ethics,ethical codes,and relevance in an international instructional technology community     

Bradshaw  Amy C.  Keller  Christopher O.  Chen  Ching-Huei 《TechTrends》2003,47(6):12-18

  相似文献   

LINKING SOCIAL–ENVIRONMENTAL RISK FACTORS WITH AGGRESSION IN SUBURBAN ADOLESCENTS: THE ROLE OF SOCIAL–COGNITIVE MEDIATORS     

Catherine P. Bradshaw  Asha Goldweber  James Garbarino 《Psychology in the schools》2013,50(5):433-450

Previous research suggests that social–cognitive factors mediate the association between social–environmental risk and aggression in high‐risk samples, but less is known about the relation among these factors in suburban youth. The present study examined whether such an association occurred for suburban youth exposed to low levels of social rejection and community violence. Using data from 184 adolescents (mean age = 14.97 years, SD = .84) and their homeroom teachers, analyses with structural equation modeling revealed a significant relation between relatively mild levels of social–environmental risk and aggression. This association was partially mediated by negatively biased social–cognitive factors (i.e., general knowledge structures and social information processing). Findings suggest that even relatively low levels of social rejection and community violence exposure characterizing suburban youth (in contrast to urban youth) put them at an increased risk for problems with aggression.  相似文献   

Cloning the Professor,an Alternative to Ineffective Teaching in a Large Course     

Jennifer Nelson  Diane F. Robison  John D. Bell  William S. Bradshaw 《CBE life sciences education》2009,8(3):252-263

Pedagogical strategies have been experimentally applied in large-enrollment biology courses in an attempt to amplify what teachers do best in effecting deep learning, thus more closely approximating a one-on-one interaction with students. Carefully orchestrated in-class formative assessments were conducted to provide frequent, high-quality feedback that allows students to accurately diagnose the current state of their understanding of fundamental biological concepts and make specific plans to remedy any deficiencies. Teachers can also assume responsibility to guide out-of-class study among classmates by promoting Elaborative Questioning, an inquiry exchange that permits misconceptions to be identified and corrected and that promotes long-lasting metacognitive and analytical thinking skills. Data are presented that demonstrate the positive impact of these innovations on student performance and affect.  相似文献   

AN EXAMINATION OF THE ASSOCIATION BETWEEN OBSERVED AND SELF‐REPORTED CULTURALLY PROFICIENT TEACHING PRACTICES     

Katrina J. Debnam  Elise T. Pas  Jessika Bottiani  Anne H. Cash  Catherine P. Bradshaw 《Psychology in the schools》2015,52(6):533-548

A critical next step in advancing our understanding of teacher practices that can equitably engage and support learning in diverse classrooms is determining the effectiveness of culturally responsive interventions. Yet, quantitative measurement indicators of the effectiveness of culturally responsive teaching interventions are scarce. Most research relies exclusively on self‐reports, with limited attention to issues of social desirability, and few studies observe teacher practices. Data come from 142 K‐8 teachers in six schools who were assessed via the Assessing School Settings: Interactions of Students and Teachers (ASSIST), an externally‐conducted observation, and who also provided self‐report data of cultural responsiveness. Analyses indicated that teachers self‐reported higher rates of culturally responsive teaching strategies than were observed on the ASSIST. There were, however, significant associations between observations and teachers’ ratings of self‐efficacy. Findings suggest a need for additional research to develop and validate efficient, multi‐informant approaches for assessing cultural responsiveness in the classroom.  相似文献   

Internet users worldwide     

Amy C. Bradshaw 《Educational technology research and development : ETR & D》2001,49(4):112-117

  相似文献   

Investigating the effect of school‐wide positive behavioral interventions and supports on student learning and behavioral problems in elementary and middle schools          下载免费PDF全文

Ji Hoon Ryoo  Saahoon Hong  William M. Bart  Jaehyun Shin  Catherine P. Bradshaw 《Psychology in the schools》2018,55(6):629-643

Many states have scaled up School‐Wide Positive Behavioral Interventions and Supports (SW‐PBIS) with the goal of improving student behavior and academic outcomes. Although the effects of SW‐PBIS on behavioral and discipline outcomes have been promising, the findings for academic achievement have been inconclusive and are often limited to cross‐sectional data. This paper examined the longitudinal effect of SW‐PBIS on student behavioral problems and academic achievement growth in elementary and middle schools using propensity score matching. We found no statistically significant longitudinal effects of SW‐PBIS on either student behavior problems or academic achievement among elementary and middle schools in this quasi‐experimental design, even though the positive direction of longitudinal changes would be identified. The result raised questions about the efficacy of SW‐PBIS using a statewide achievement test when scaled up to a state level. Additional research is needed to better understand the impact of SW‐PBIS using rigorous scale‐up designs.  相似文献   

The Librarian's Legal Companion for Licensing Information Resources and Services,by Tomas A. Lipinski     

Lori Bradshaw 《Medical reference services quarterly》2013,32(4):475-476

  相似文献