This study illustrates an integrative psychometric framework to investigate two sources of construct-relevant multidimensionality in answers to the Self-Perception Profile for Children (SPPC). Using a sample of 2,353 German students attending Grades 3 to 6, we contrasted: (a) first-order versus hierarchical and bifactor models to investigate…

Early adolescents vary in their susceptibility to peer influence on delinquency. However, it is still less clear which factors explain this variation and how these factors relate to each other. In this study, 10 factors that may moderate peer influence were investigated. A sample of 868 participants was followed across six occasions from seventh…

This research is motivated by an analysis of reading research data. We are interested in modeling the test outcome of ability to fluently recode letters into sounds of kindergarten children aged between 5 and 7. The data showed excessive zero scores (more than 30% of children) on the test. In this dissertation, we carefully examine the models…