Adolescents typically exhibit a marked decline in academic intrinsic motivation throughout their school careers. Following self-determination theory, it is hypothesised that traditional school environments insufficiently satisfy three basic psychological needs of youths during maturation, namely the needs for autonomy, competence and relatedness.…

The data collection of a cohort study requires making many decisions. Each decision may introduce error in the statistical analyses conducted later on. In the present study, a procedure was developed for estimation of the error made due to the composition of the sample, the item selection procedure, and the test equating process. The math results…