Background: Most knowledge on early child development stems from cross-sectionally testing children of different ages. However, uncovering individual developmental trajectories requires a high-density longitudinal approach, which can be achieved by outsourcing the data collection to parents who assess the everyday life behavior of their children. The usefulness of such approaches has also become apparent in light of the current COVID-19 pandemic, which limited access to laboratories.
Method: The “kleineWeltentdecker App” (Daum et al., 2020) is an easy-to-use smartphone-based developmental diary app integrating a population-based, prospective, and microgenetic approach with the age-of-attainment method. Parents of children from 0-6 years can track the development of their children in different domains (cognitive, motor, language, and social-emotional skills). Parents answer questions matched to the children’s age, covering the entire period in which particular skills are expected to change.
Results: We will present preliminary results based on the first > 3000 children whose development was documented using the app. We analyzed parents’ and children’s characteristics relative to population characteristics and described parents’ user behavior. On average, parents answered 71 questions over 49 day; however, there was large variability in user behavior. Further, more than 70% of data points were generated in children’s first and second year.
Discussion: These results help to understand how a smartphone app to document early child development was used by parents and which samples were obtained using this method. We also discuss ways to increase the reach of the app – including expanding its use to non-WEIRD countries.