Scientific knowledge in STEM contributes to technological, economic and societal progress, which is why a basic understanding of the process of gaining scientific knowledge is important. Experimentation skills play a central role in this, as they link all STEM sciences. At the same time, numerous studies show that knowledge and competences acquired in one subject can hardly be transferred to other subject contexts or interdisciplinary learning environments. The aim of our project is to establish experimentation as an interdisciplinary effective STEM competence. In doing so, both cognitive abilities and skills as well as the expectation of self-efficacy are to be considered. Particularly when considering an increasingly heterogeneous student body, the question arises as to what extent it is possible to promote experimentation in the best possible way, taking into account individual prerequisites, social background and gender, supported by modern subject didactics and teaching/learning psychological approaches in an interdisciplinary manner. Based on a model of interdisciplinary STEM experimentation competence and considering the potential of digital learning formats, adaptive measures, especially in the form of different instructions, will be developed for this purpose and their effect on improving experimentation competence in interdisciplinary learning environments will be analysed. From this, hints and recommendations for the design of instructions for the individual promotion of the experimental competence of students will be derived, which can increase equal opportunities for learners who have so far been educationally disadvantaged in the STEM area.