ASSIST-ME is a high level research project with a societal impact that will investigate formative and summative assessment methods to support and to improve inquiry-based approaches in European science, technology and mathematics (STM) education. Based on an analysis of what is known about summative and formative assessment of knowledge, skills and attitudes related to key STM competences and an analysis of European educational systems, the project will design a range of combined assessment methods. These methods will be tested in primary and secondary schools in different educational cultures in Europe in order to analyse the conditions that support or undermine the uptake of formative assessment related to inquiry processes.The resulting synthesis of opportunities and restrictions for implementing an assessment culture using both formative and summative approaches will be evaluated and discussed in relevant forums in order to formulate guidelines and recommendations for policy makers, curriculum developers, teacher trainers and other stakeholders in the different European educational systems.