The author shows how the copulas can be used to analyze repeated measurements with missing data. The main problem in practice is that there does not exist any theoretical joint distribution describing the repeated measurements, and then the copula function is a good tool to create the joint distribution. As the measurements are, in general, dependent, the conditional distribution of measurement...

Statistical models for calculating sample sizes for controlled clinical trials often fail to take into account the negative impact that dropouts have on the power of intent-to-treat analyses. Empirically defined dropout correction coefficients are proposed to adjust sample sizes for endpoint analysis of variance (ANOVA) and analysis of covariance (ANCOVA) that have been initially calculated ass...

BACKGROUND Indicators of the level of education are the most important parameters influencing each country's development. Social indicators considered to be a determinant of one's health consists of two constituents namely; (1) Rate of students enrolled in elementary, guidance, secondary and higher education and (2) the rate of adult literacy. This study is aimed to evaluate the situation of sc...

This paper focuses on university-level education offered by methods of distance learning in the field of computers and aims at the investigation of the main causes for student dropouts. The presented study is based on the students of the Course of ‘‘Informatics’’, Faculty of Science and Technology of the Hellenic Open University and investigates the particularities of education provided through...