Reducing Gender Consolidation to Promote Friendship Diversity in Schools: An Interactive Web Application for a Field Experiment on Class Assignments

This interactive R Shiny web application was developed as the treatment in a field experiment on class assignments conducted as part of the project "Sorting Decisions and Peer Processes in Schools (SPINS)". The application informs class list coordinators (the school personnel responsible for class assignments) about the relationship between gender consolidation and friendship segregation (Böller and Kruse 2025) and presents a sorting heuristic designed to minimize the consolidation of gender with another social category in class assignments. Through an instructional video, a detailed example, and an interactive quiz, the application guides class list coordinators through three steps: (1) Decide in relation to which category they would like to foster friendship diversity, (2) form student subgroups by combining the chosen category with gender, and (3) evenly distribute these subgroups across classes. This procedure minimizes the consolidation of the selected category and gender. Rather than prescribing a specific category, the application allows class list coordinators to determine which category is most relevant in their context. To provide concrete and realistic examples while avoiding a uniform focus on a single category, schools randomly received one of eight example categories in the web application (academic achievement, parental education, first language, former elementary school, religion, parental countries of birth, special educational needs, or refugee status). In March 2024, before students entering fifth grade were assigned to classes for the upcoming school year, we administered the web application to 68 randomly selected secondary schools. Thirty-three randomly selected schools were assigned to the control group and received access to the application after the experiment. The web application was created as part of the project "Sorting Decisions and Peer Processes in Schools (SPINS)" led by Hanno Kruse and funded by the Deutsche Forschungsgemeinschaft (DFG) – KR 5529/1-1. The embedded video was produced under the direction of Senami Hotse.