Educational researchers often aim for their research to be used to inform and change practice. But experience tells us that it is not easy for research to affect policy. A central goal in the highlevel European research project, ASSISTME (Assess Inquiry in Science, Technology and Mathematics Education), is to formulate guidelines and recommendations for policy makers, curriculum developers, teacher trainers and other stakeholders in European educational systems. This use of research results is organized through National Stakeholder Panels established to advise and provide professional development on how best to impact policy and practice. In this paper, we report on a method to map out networks of relevant stakeholders and use Social Network Analysis to select key stakeholders to invite to National Stakeholder Panels in seven European countries. Our analysis shows that size and coherency of networks are crucial factors when project partners use Social Network Analysis reports to select members to invite to National Stakeholder Panels. Other factors, such as perceived bias in the kinds of stakeholders and lag of knowledge of stakeholders in the networks are also important. The results are useful to researchers who want to engage with systematic mappings of stakeholders for science educational policy projects.