Digital Module 16: Longitudinal Data Analysis     

Jeffrey R. Harring  Tessa L. Johnson 《Educational Measurement》2020,39(3):137-138

In this digital ITEMS module, Dr. Jeffrey Harring and Ms. Tessa Johnson introduce the linear mixed effects (LME) model as a flexible general framework for simultaneously modeling continuous repeated measures data with a scientifically defensible function that adequately summarizes both individual change as well as the average response. The module begins with a nontechnical overview of longitudinal data analyses drawing distinctions with cross-sectional analyses in terms of research questions to be addressed. Nuances of longitudinal designs, timing of measurements, and the real possibility of missing data are then discussed. The three interconnected components of the LME model—(1) a model for individual and mean response profiles, (2) a model to characterize the covariation among the time-specific residuals, and (3) a set of models that summarize the extent that individual coefficients vary—are discussed in the context of the set of activities comprising an analysis. Finally, they demonstrate how to estimate the linear mixed effects model within an open-source environment (R). The digital module contains sample R code, diagnostic quiz questions, hands-on activities in R, curated resources, and a glossary.  相似文献   

Effects of light refraction on the accuracy of camera calibration and reconstruction in underwater motion analysis   总被引：1，自引：0，他引：1  

Kwon YH  Casebolt JB 《Sports biomechanics / International Society of Biomechanics in Sports》2006,5(2):315-340

One of the most serious obstacles to accurate quantification of the underwater motion of a swimmer's body is image deformation caused by refraction. Refraction occurs at the water-air interface plane (glass) owing to the density difference. Camera calibration-reconstruction algorithms commonly used in aquatic research do not have the capability to correct this refraction-induced nonlinear image deformation and produce large reconstruction errors. The aim of this paper is to provide a thorough review of: the nature of the refraction-induced image deformation and its behaviour in underwater object-space plane reconstruction; the intrinsic shortcomings of the Direct Linear Transformation (DLT) method in underwater motion analysis; experimental conditions that interact with refraction; and alternative algorithms and strategies that can be used to improve the calibration-reconstruction accuracy. Although it is impossible to remove the refraction error completely in conventional camera calibration-reconstruction methods, it is possible to improve the accuracy to some extent by manipulating experimental conditions or calibration frame characteristics. Alternative algorithms, such as the localized DLT and the double-plane method are also available for error reduction. The ultimate solution for the refraction problem is to develop underwater camera calibration and reconstruction algorithms that have the capability to correct refraction.  相似文献   

Effects of Mass and Interpersonal Communication on Breast Cancer Screening: Advancing Agenda-Setting Theory in Health Contexts     

Karyn Ogata Jones  Bryan E. Denham  Jeffrey K. Springston 《Journal of Applied Communication Research》2006,34(1):94-113

Drawing on components of agenda-setting theory and the two-step flow of information from mass media to news audiences, this study examines the effects of mass and interpersonal communication on breast cancer screening practices among college- and middle-aged women (n = 284). We theorized that screening behaviors among younger women would be influenced more by interpersonal sources of information while screening among middle-aged women would be more influenced by exposure to mass-mediated information. Findings supported anticipated patterns, revealing important and varying roles for both mass and interpersonal communication in the health behaviors of women. Implications for health practitioners and campaign planners, as well as recommendations for future research, are discussed.  相似文献   

F2F connection: a community health information needs assessment of Texas families who have children with chronic illnesses and/or disabilities and their care providers.     

Jeffrey T Huber  Jill D Dietrich  Eve Cugini  Shannon Burke 《Journal of the Medical Library Association》2005,93(2):278-281

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Conservative Bias: How Jesse Helms Pioneered the Rise of Right‐Wing Media and Realigned the Republican Party Bryan Hardin Thrift. Gainesville: University Press of Florida, 2014.          下载免费PDF全文

Jeffrey T. Ramsey 《Journal of American culture (Malden, Mass. : 2003)》2016,39(2):247-247

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Estimating fat-free mass in elite-level male rowers: a four-compartment model validation of laboratory and field methods     

Kristina L. Kendall  David H. Fukuda  Parker N. Hyde  Abbie E. Smith-Ryan  Jordon R. Moon  Jeffrey R. Stout 《Journal of sports sciences》2017,35(7):624-633

The purpose of this study was to investigate the accuracy of fat-free mass (FFM) estimates from two-compartment (2C) models including air displacement plethysmography (ADP), ultrasound (US), near-infrared interactance (NIR), and the Jackson and Pollock skinfold equation (SKF) against a criterion four-compartment (4C) model in elite male rowers. METHODS: Twenty-three elite-level male rowers (mean± SD; age 24.6 ± 2.2 years; stature: 191.4 ± 7.2 cm; mass: 87.2 ± 11.2 kg) participated in this investigation. All body composition assessments were performed on the same day in random order, except for hydrostatic weighing (HW), which was measured last. FFM was evaluated using a 4C model, which included total body water from bioimpedance spectroscopy, body volume from HW, and total body bone mineral via dual-energy X-ray absorptiometry. The major findings of the study were that the 2C models evaluated overestimated FFM and should be considered with caution for the assessment of FFM in elite male rowers. Future studies should use multiple-compartment models, with measurement of TBW and bone mineral content, for the estimation of FFM.  相似文献   

Allegany to Appomattox: The Life and Letters of Private William Whitlock of the 188th New York Volunteers Valgene Dunham. Syracuse,NY: Syracuse University Press, 2013.          下载免费PDF全文

Jeffrey P. Cain 《Journal of American culture (Malden, Mass. : 2003)》2015,38(3):276-277

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Factorial Invariance of the Abbreviated Neighborhood Environment Walkability Scale among Senior Women in the Nurses’ Health Study Cohort     

Heather A. Starnes  Meghan H. McDonough  Jeffrey S. Wilson  Daniel K. Mroczek  Francine Laden  Philip J. Troped 《Measurement in physical education and exercise science》2019,23(2):135-147

The purpose of this study was to examine the factorial invariance of the Abbreviated Neighborhood Environment Walkability Scale (NEWS-A) across subgroups based on demographic, health-related, behavioral, and environmental characteristics among Nurses’ Health Study participants (N = 2,919; age M = 73.0, SD = 6.9 years) living in California, Massachusetts, and Pennsylvania. A series of multigroup confirmatory factor analyses were conducted to evaluate increasingly restrictive hypotheses of factorial invariance. Factorial invariance was supported across age, walking limitations, and neighborhood walking. Only partial scalar invariance was supported across state residence and neighborhood population density. This evidence provides support for using the NEWS-A with older women of different ages, who have different degrees of walking limitations, and who engage in different amounts of neighborhood walking. Partial scalar invariance suggests that researchers should be cautious when using the NEWS-A to compare older adults living in different states and neighborhoods with different levels of population density.  相似文献   

单板滑雪U型场地技巧优秀运动员落地稳定性研究     

阚军常  李嘉  潘立权  赵晨琼  吕婵  李兴洋  谭睿 《哈尔滨体育学院学报》2017,35(3)

近年来,随着单板滑雪U型场地技巧项目的快速发展及国际运动成绩的快速提升,我国运动员在训练方面遇到了很多问题,如运动员在完成高难度的空中技术动作后,在落地时总是出现失误,直接影响运动员在比赛中的成绩.本文采用文献资料、专家访谈、录像分析等研究方法,对黑龙江省单板滑雪U型场地技巧优秀运动员的落地稳定性进行了分析,具体涉及运动员成套动作落点分析、滑行路线分析和运动员平衡能力,研究结果认为,运动员的平衡能力差和落点区域的不同选择是导致落地稳定性差的主要原因.为帮助单板滑雪U型场地技巧项目备战2018年平昌冬奥会提供了一定的理论依据.  相似文献   

Meeting players where they are: Digital games and learning ecologies     

Donatella Persico  Marcello Passarelli  Francesca Pozzi  Jeffrey Earp  Francesca Maria Dagnino  Flavio Manganello 《British journal of educational technology : journal of the Council for Educational Technology》2019,50(4):1687-1712

This paper explores the relationship between digital games and learning along the continuum from formal to informal learning. Games are an increasingly important component of our learning ecologies but their potential can prove difficult to fully harness due to the downsides of gaming in informal contexts and to the limitations games can present when adopted in formal learning contexts. The aim of this paper is to shed light on the strengths and weaknesses of games for learning, and to gather stakeholder recommendations for the main actors in the field. The adopted research approach is qualitative and participatory, involving players, teachers, parents, researchers and developers. Data from 25 interviews and 11 focus groups yielded insights into the educational, psychological and ethical aspects of play. Results suggest that gameplay influences individuals in a very personal manner, and that its effects cover a wide range of skills, extending to identity development. Hence, to harness this potential, all actors in the ecology need strong awareness of both the affordances and the risks of games, and deep respect for individuals’ LEs. The study has implications for a wide range of actors, including educators, players, researchers, parents, game developers and policymakers.  相似文献