Technological design is a core activity in Science, Technology, Engineering and Mathematics (STEM) education. During the design process, students often employ research activities to enhance the quality of their design decisions and to rise above a mere trial-and-error approach to designing. There are many functions of research within the design process, for example theoretical research, user research, or testing a prototype. In this study, we aimed to examine student and teacher perceptions of the functions of research in the context of a design-oriented STEM module in Dutch secondary education. To do so, we first examined in what ways students and teachers who conducted or respectively taught the STEM module recognized functions of research within design. We also looked at the value students attributed to these functions, and how teachers described their facilitation of the functions of research within design. During the STEM module, students conducted a design project related to an authentic problem in biomedical technology, while using research activities to support their design decisions. Results from student focus groups and teacher interviews showed that they recognized several ways in which research activities contribute to a design process. Students valued the functions of research within design as important for the end product, although some students preferred to skip research and start building their design right away. Some teachers employed strategies to ensure students learned to do research steps, for example by a reverse design exercise. The results from this study raise the question whether all students should apply research activities in the same order during a design process, since different students seem to prefer different ways of designing. A design-oriented STEM module like this one is an appropriate way to start showing students the functions of research within design, however differentiation between different students’ preferences could possibly enhance this learning process.