Mobile devices are increasingly being used, in various ways, to collect data and are also increasingly related to individuals' health behaviors. Because of the paucity of available data about the process of mobile data collection in tracking daily health behaviors among children, we designed this pilot study to determine the possibilities and the…

Introduction: The aim of this study was to evaluate the school-based "My Body and I" program which was designed to help girls and boys to cope better with inevitable pubertal body changes. Method: Using a pre-post treatment-control design with 25 treatment and 17 control classes from schools in Germany and France (484 boys, 485 girls;…

The objective of this work was to highlight the conceptions of force held by students aged 10-17 years old, in situations where animate and inanimate objects interact. In the proposed experimental situations, we varied parameters such as the motion and position of an object and the agent's effort. We asked questions about both inanimate and…

165 students, from the fifth, seventh and ninth grades were asked to solve written problems involving fractions. In the problems a reference quantity (RQ) was multiplied by a fraction (FR), yielding the value of a compared quantity (CQ). The fraction expressed either an part-whole ratio (PW), or a part-part ratio (PP). Six type of problems were…