The aim of the European H2020 project MULTIPLIERS is to expand science learning opportunities by fostering cooperation between schools and society and involving the students in real-life projects. To achieve this, the project has established novel learning partnerships (“Open Science Communities” = OSCs) where schools, families, research institutions, industry, informal learning providers, policy makers and media collaborate in order to foster the students’ engagement with contemporary challenges. In these learning projects (“Open School Science learning projects = OSS projects), the students work with various stakeholders to explore different perspectives and improve their understanding while gaining first-hand experiences and an insight into research practices and discussions. The students then act as “multipliers” and share their knowledge and experiences by actively involving their families and the wider community, through dedicated multiplying events (e.g., open-school days), or the production of science communication media (e.g., podcasts and video clips). In our presentation, we will focus on three biology education case studies from Germany, Slovenia and Sweden, where OSCs have been established, and students and science experts worked together on different socio-scientific issues. For the evaluation of the OSS projects, we used qualitative data from participant observations and interviews as well as focus group discussions with the participants (i.e., students, teachers, science experts, families, and community members). Our data were used to derive information about successful methodological approaches and learning environments. The data show that the engagement in scientific practices using authentic equipment triggered the students’ interest. High engagement and students’ interest was also observed and reported for the different debate activities. It was found that promoting the students’ autonomy and leadership, while taking on the role of knowledge multipliers, fostered their interest, self-efficacy and knowledge acquisition. Students were particularly positive about out-of-school experiences in authentic settings, opportunities to work independently in groups, and about the support of the experts. In the MULTIPLIERS project, further OSS projects will be conducted and evaluated in order to derive final recommendations and publish guidelines and materials for successful open schooling activities.