Validating a shortened form of the ARC for special populations

Autonomy describes cognition or behavior that is self-directed, according to personal interests, and free from external influence. This construct is of importance to students who are deaf because it has been shown to be positively related to their post-school transition outcomes, and this population faces unique challenges in this area. To conduct research with this construct, it is necessary to use measures that are valid and reliable for the population of interest. Therefore, a set of exploratory and confirmatory factor analyses validated the unidimensionality of a shortened form of the ARC Self-Determination Scale’s autonomy dimension. A three-factor solution, including a social skills dimension, was measurement-invariant across many groups of students, including those with learning disabilities, emotional disturbances, speech and language impairments, and other health impairments. Although the shortened form of this scale was not unidimensional, as hypothesized, the generalizability of its measurement properties may prove useful. Discussion highlights the differences between these three dimensions and Wehmeyer's theory of self-determination.     

Assessing Measurement Invariance in Multiple-Group Latent Profile Analysis

The study of measurement invariance in latent profile analysis (LPA) indicates whether the latent profiles differ across known subgroups (e.g., gender). The purpose of the present study was to examine the impact of noninvariance on the relative bias of LPA parameter estimates and on the ability of the likelihood ratio test (LRT) and information criteria statistics to reject the hypothesis of invariance. A Monte Carlo simulation study was conducted in which noninvariance was defined as known group differences in the indicator means in each profile. Results indicated that parameter estimates were biased in conditions with medium and large noninvariance. The LRT and AIC detected noninvariance in most conditions with small sample sizes, while the BIC and adjusted BIC needed larger sample sizes to detect noninvariance. Implications of the results are discussed along with recommendations for future research.     

边界条件下的电磁场的正则量子化

利用Fadecv-Jakiw方法对带边界条件的电磁场进行量子化,将场变量的傅里叶展开的模作为新的动力学变量获得对易关系,所有的量子化过程都在经典解空间进行。计算了两无穷平行平面边界的Casimir能。     

一个可能最终确定以太存在与否的实验

分析了“光行差”现象、“光速不变”现象、“洛奇钢盘实验”,认为地球有可能拖曳以太。论证了在绕地轨道上进行迈克尔逊一莫雷实验可以最终确定是否存在以太,并设计了相应的设备。     

Recent Developments in Measurement and Possible Applications to the Measurement of Psychomotor Behavior

Abstract

Elementary physical education instructors and movement development clinicians frequently employ movement observation as their primary assessment strategy. The purpose of this study was to determine the minimal conditions of observation needed to obtain generalizable results across observers, trials, and subjects for the hop, jump, and run. The developmental sequences developed at Michigan State University were used as the observation system. Twelve children in the age range of 33–111 months were rated on five trials by 15 observers. The sample consisted of an equal number of males and females and did not involve children with handicapping conditions. The results suggest that when observers receive 1 hour of training for each skill, one observer and three trials are needed for evaluating the hop (.88), while three observers and three trials are required for the jump (.83). None of the nine measurement conditions resulted in acceptable (.80) generalizability for the run.     

Muscle Soreness Following Resistance Exercise With and Without Eccentric Contractions

The present study reported on translating the Exercise Identity Scale (EIS: Anderson &; Cychosz, 1994) into Greek and examining its psychometric properties and cross-cultural validity based on U.S. individuals' EIS responses. Using four samples comprising 33, 103, and 647 Greek individuals, including exercisers and nonexercisers, and a similar sample comprising 800 U.S. individuals, the concurrent validity, factor structure, internal reliability, test-retest reliability, external validity, gender invariance, and cross-cultural validity of the EIS responses were examined using confirmatory factor analytical procedures. The results supported the concurrent validity, an adequate unidimensional factor structure for the translated EIS and the internal reliability and test-retest reliability over a 6-week interval. Further, cross-gender configural, partial metric, partial strong factorial, and partial strict factorial invariance and cross-cultural configural and partial metric invariance supported the cross-cultural equivalence of the EIS versions. Moreover, the external validity of the translated EIS responses was also supported. Overall, the findings supported the validity of the exercise identity construct outside North American boundaries and the EIS items' equivalence, providing initial evidence for its cross-cultural applicability.     

Coaching competency and satisfaction with the coach: A multi-level structural equation model

Abstract

The purpose of this initial predictive validity study was to determine the ability of measures derived from the Athletes' Perceptions of Coaching Competency Scale II – High School Teams (APCCS II-HST) to predict satisfaction with the head coach. Specification of the statistical model was informed by the mediational model of coach–athlete interactions. The technical quality of the satisfaction measure was evaluated before testing the predictive validity of the coaching competency measures. Data were collected from athletes of seven sports. Athlete observations (N = 748) were clustered within teams (G = 74). Multi-group confirmatory factor analyses (CFA) provided evidence for factorial invariance of a reduced version of the satisfaction measure by athlete gender. Multi-level CFA provided evidence of model–data consistency for a reduced version of the satisfaction measure. Multi-level structural equation modelling provided evidence for the ability of latent coaching competency to positively predict latent satisfaction at both the athlete level (technique competency and motivation competency) and the team level (coaching competency) and for close model–data fit. Implications of this study include: that the APCCS II-HST should be viewed as a replacement for the Coaching Competency Scale when the intended population is appropriate; a preliminary multi-level measurement model for satisfaction with one's coach that should be considered as a potential starting point in subsequent studies; and empirical support for a key relationship proposed in the mediational model of coach–athlete interactions.     

Factor Structure and Measurement Invariance of a 10-Item Decisional Balance Scale: Longitudinal and Subgroup Examination Within an Adult Diabetic Sample

This study explores the longitudinal and subgroup measurement properties of a 10-item, physical activity decisional balance scale, previously published by Plotnikoff, Blanchard, Hotz, and Rhodes (2001 Plotnikoff, R. C., Blanchard, C., Hotz, S. B. and Rhodes, R. 2001. Validation of the decisional balance scales in the exercise domain from the Transtheoretical Model: A longitudinal test. Measurement in Physical Education and Exercise Science, 5: 191–206. [Taylor & Francis Online] , [Google Scholar]), within a diabetic sample of Canadian adults. Results indicated that a three-factor measurement model consistently improved model fit compared to the previously published two-factor model. Evidence of configural, metric, and scalar measurement invariance across time and among subgroups suggests that the 10-item decisional balance scale is appropriate for investigating associative relationships with other constructs and for comparing group means of the pros and cons subscales among a variety of diabetic population subgroups.     

Factorial Validity and Reliability of the Curricular Goals in Physical Education Questionnaire

This study aimed to examine the validity and reliability of an instrument designed to measure student perceptions of curricular goals in physical education, the Curricular Goals in Physical Education Questionnaire. Participants were 879 Finnish students from grades 7 to 9 (412 girls, 467 boys; mean age 13.81). An exploratory factor analysis was performed on Sample 1 (n = 287), revealing a four-factor solution and suggesting that factor structure be cross-validated with confirmatory factor analysis in Sample 2 (n = 592). Confirmatory factor analysis demonstrated an acceptable fit and supported the four-factor model. Tests for gender invariance supported configural, metric, and scalar invariance. Analyses of factor mean differences indicated that girls attributed more importance than boys to physical education’s health-related goals, social and emotional learning, and motor skill development. This study confirmed the validity of the Curricular Goals in Physical Education Questionnaire to assess student perspectives on curricular goals across gender. In order to improve factor structure the authors suggest the addition of an item measuring skill acquisition to future versions of the instrument.     

Form Invariance, Noether and Lie Symmetry of Non-conservative Hamiltonian Systems in Phase Space

For the non-conservative holonomic Hamiltonian systems in phase space, the definition and criteria of the form invariance of the generalized Hamilton canonical equations were given. The relations among the form invariance, Noether symmetry and Lie symmetry were studied. The theory of the form invariance for the conservative holonomical systems was worked out. An example was given to illustrate the results.