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This study meta-analyzes thirty-nine study results published within last ten years that directly compared Web and mail survey modes. Although considerable variation exists across the studies, the authors' findings show that mail surveys have higher response rates than Web surveys in general. Two study features (i.e., population types and follow-up reminders) are shown to contribute statistically to the variation of response rate differences between Web and paper surveys in the comparative studies. College respondents appear to be more responsive to Web surveys, while some other respondents (e.g., medical doctors, school teachers, and general consumers) appear to prefer traditional mail surveys. Follow-up reminders appear to be less effective for Web survey respondents than for mail survey respondents. Other study features (i.e., implementation of random assignment of survey respondents, incentives, and publication year) are not statistically useful in accounting for the variation of response rate differences between Web and mail surveys.

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clinicaltrials.gov Identifier: NCT00848900.

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The literature related to Borg's ratings of perceived exertion (RPE) scale has revealed inconsistencies about the strength of the relationship between ratings of perceived exertion and various physiological criterion measures, such as heart rate, blood lactate concentration, percent maximal oxygen uptake (%VO2max), oxygen uptake (VO2), ventilation and respiration rate. Using sex of participants, fitness, type of RPE scale used, type of exercise, exercise protocol, RPE mode and study quality, we undertook a meta-analysis to determine the strength of the relationship between RPE scores and the six aforementioned physiological measures. The weighted mean validity coefficients were 0.62 for heart rate, 0.57 for blood lactate, 0.64 for %VO2max 0.63 for VO2, 0.61 for ventilation and 0.72 for respiration rate. Analysis of moderator variables revealed that the following study features could account for the variation of results across studies: heart rate--fitness, type of exercise, protocol and RPE mode; blood lactate concentration--sex, RPE scale; VO2--sex, exercise type, RPE mode; ventilation--sex, RPE mode; respiration rate--exercise protocol, RPE mode. The highest correlations between ratings of perceived exertion and the various physiological criterion measures were found in the following conditions: when male participants (whose VO2 or ventilation was measured) were required to maximally exert themselves (measuring %VO2max or ventilation); when the exercise task was unusual [e.g. when participants were swimming, which is less common than walking or running (when heart rate, %VO2max and VO2 are measured)]; or when the 15-point RPE scale (measuring blood lactate concentration) was used. These findings suggest that although Borg's RPE scale has been shown to be a valid measure of exercise intensity, its validity may not be as high as previously thought (r = 0.80-0.90), except under certain conditions.

In this study we examined authoritative discipline theory, which posits that 2 complementary aspects of school climate—structure and support—are important for adolescents' safety in school. Using a statewide sample of over 7,300 ninth-grade students and 2,900 teachers randomly selected from 290 high schools, we showed, using hierarchical linear modeling, that consistent enforcement of school discipline (structure) and availability of caring adults (support) were associated with school safety. Structure and support were associated with less bullying and victimization after we controlled for size of school enrollment and the proportion of ethnic minority and low-income students. These findings suggest that discipline practices should not be polarized into a “get tough” versus “give support” debate because both structure and support contribute to school safety for adolescents.