The COST EU Action “Determinants of Physical Activities in Setting” (DE-PASS, CA19101) has developed evidence-informed methodologies to examine PABs and their associated determinants in youth, providing a harmonized, best practice data collection methodology for the examination of PABs and their associated determinants across a broad range of European nations. The purpose of the proposed study is to conduct/participate in a Proof of Concept pilot data collection to implement the developed methodologies for evaluating PABs and their associated determinants in Ireland, aligning with data collection being conducted across 10 EU nations including Belgium, Croatia, Czech Republic, Malta, Montenegro, Norway, Portugal, Slovenia and the Netherlands. The study procedure itself will be described below. PABs and their determinants within the Family, Home and School Setting (Child-Adolescent aged 9-12 years) will be the focus of the DE-PASS Proof of Concept Data Collection. The primary participant in this study is the study child, a child aged between 9-12 years that attends a school that has been identified for inclusion within this research. As part of this research, it is important for the examination of distal influencers for PABs, which include the primary caregiver (i.e., mother, father, guardian) and siblings (i.e., brother, sister if applicable). For a sibling to be eligible for participation, they must be aged between 8-17 years. The minimum participant numbers is 50 families. Data about morphological characteristics will be measured using standard anthropometric procedures. PABs associated determinants will be collected using standard questionnaires. While Physical Activity Behaviors (PABs) will be measured using ActiGraph Devices. All subjects included in the study will wear ActiGraph Devices for a period of 8 consecutive days, and periodically communicate with the research team. After the end of the examination procedure, reports and data analysis will be prepared, as well as their presentation to the scientific public.