Ethics
Ethics was an integral part of this study from beginning to end and included an approval by the European Research Council Executive Agency, by an ethics committee from the University of Munich, the Department of Education and Sports, Munich, and the Bavarian Ministry of Education.
Sampling
The first cohort of our sample consisted of N=190 children with their families at t1. The second cohort consisted of N=310 children and their families at t1. In total, N=151 families were randomly assigned to each intervention groups, N=98 were assigned to the tablet-control group and N=100 were assigned to the control group without tablets. Consent forms, plain language statements, and parental surveys were translated into several languages. In addition, educator and teacher surveys were developed and used that focused on evaluating children’s behavior. Further, a team of researchers and research assistants were trained and conducted all seven assessments for both cohorts in kindergartens and primary schools with N=380 families still participating in the last assessment of the project.
Tablets, server system, tablet apps, and content
Android tablets (N=410) were prepared to be used in the intervention. In addition, a server system with three different servers was used to monitor the tablets and the individual app usage as well as to monitor the weekly progress of each tablet.
Our apps were mostly designed and developed by our team with IT support and targeted literacy, numeracy and general cognitive skills. These apps were installed via the server system. New apps were installed automatically every month via Wi-Fi connection and parents received weekly tips via the tablet. App usage data was logged at regular intervals for each tablet and synchronized on a regular basis with the backend server.
Further, parental guidelines and tips were provided via the tablet. The tablets also contained e-books, audiobooks, interactive books, and music. For this purpose, these media files were carefully selected and the families received different material depending on their assigned group.
Results and dissemination
All hypotheses were confirmed: The home learning environment acted as a mediator between family background variables and child outcomes, the app intervention supported children’s learning in each specific domain and longer app usage times were associated with greater gains. Research findings in the context of the study were published in 17 peer-reviewed papers until May 2025. Further manuscripts were submitted for peer review and additional papers will be prepared. In addition, the findings were presented in a scientific one-day conclusive symposium to researchers and the public and in interviews and social media information about the project and its findings were provided.
