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The cohort growth model (CGM) is a method for estimating the parameters of a latent growth model (LGM) based on cross-sectional data. The CGM models the interindividual differences in the growth rate, and it models how subjects’ growth rate is related to their initial status. We derive model identification for the CGM and illustrate, in a simulation study, that the CGM provides unbiased parameter estimates in most simulation conditions. Based on empirical data we compare the estimates of the CGM with the estimates of the LGM. The results were comparable for both models. Although the estimates of the (co)-variances were different, the estimates of both models led to similar conclusions on the developmental change. Finally, we discuss the advantages and limitations of the CGM, and we provide recommendations for its use in empirical research. 相似文献
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Bruce Jost Carolyn Rude-Parkins Rod P. Githens 《Community College Journal of Research & Practice》2013,37(9):656-669
This study investigated the effects the demographic variables age, gender, and ethnicity and their interactions had on academic performance in online courses delivered by public two-year colleges in Kentucky. The study controlled for previous academic performance measured by cumulative grade point average (GPA). The study used a random sample (N = 320) of all students who had enrolled in at least one online course delivered by the institutions of the Kentucky Community and Technical College System in the spring 2008 semester. A linear hierarchical multiple regression acting as ANCOVA served as the main analysis, with the order entry as follows: cumulative GPA; independent variables (age, gender, ethnicity); interaction vectors; and product vectors. Final course grade served as the dependent variable. The results of the analysis indicated that only cumulative GPA was a significant predictor, explaining approximately 40% of the variance of the final grade. Although differences in final grades were present among the variables age and ethnicity, these differences disappeared when controlling for cumulative GPA. Significance of the results and recommendations for future research are discussed. 相似文献
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Jost Nathanael S. Jossen Sina L. Rothen Nicolas Martarelli Corinna S. 《Education and Information Technologies》2021,26(3):3097-3113
Education and Information Technologies - Ongoing digital transformations facilitate the conduct of online courses and distance learning. In this study, it was aimed to investigate the role of... 相似文献
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The Partner Group works on topics in geometric analysis in cooperation with the corresponding research group at the Max Planck Institute for Mathematics in the Sciences in Leipzig. 相似文献
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Dejan Reljic Joachim Jost Kirsten Dickau Ralf Kinscherf Gabriel Bonaterra Birgit Friedmann-Bette 《Journal of sports sciences》2015,33(5):437-448
Dietary intake, vitamin status and oxidative stress were evaluated in 17 elite male boxers. Ten of them frequently reduced body weight rapidly before competitions (Weight Loss Group) and 7 did not practice rapid weight loss (Control Group). Food record checklists, blood samples for determination of vitamin status and plasma glutathione levels were obtained during a week of weight maintenance, a pre-competition week and a post-competition week. The average dietary intakes in both groups were 33 ± 8 kcal·kg?1, 3.7 ± 1.1 g·kg?1 carbohydrates, 1.5 ± 0.4 g·kg?1 protein, 1.2 ± 0.4 g·kg?1 fat and 2.2 ± 1.0 L water per day (excluding pre-competition week in Weight Loss Group). Energy (18 ± 7 kcal·kg?1), carbohydrate (2.2 ± 0.8 g·kg?1), protein (0.8 ± 0.4 g·kg?1), fat (0.6 ± 0.3 g·kg?1) and water (1.6 ± 0.6 L) consumption (P-values <0.001) and intakes of most vitamins (P-values < 0.05) were significantly reduced during the pre-competition week in the Weight Loss Group. In both groups, the intakes of vitamins A, E and folate were below recommended values throughout the three periods; however, blood vitamin and plasma glutathione levels did not change significantly. Our findings indicate a low-caloric and low-carbohydrate diet in elite boxers, regardless of participating in rapid weight loss or not. Apparently, the pre-competitional malnutitrition in the Weight Loss Group did not induce alterations in the vitamin and glutathione status. 相似文献
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