Design activities are increasingly used in science, technology, engineering and mathematics (STEM) education. Guiding students during these activities can be challenging for STEM teachers, who may be inexperienced in the field of design. In this study, we focused on a case of three chemistry teachers who implemented design projects in their classrooms. During the lessons, the students designed a self-heating or self-cooling cup, in which the energy effect of chemical reactions causes a heating or cooling effect on the cup’s contents. Through an in-depth analysis of the conversations between the teachers and student groups, we aim to understand how teachers verbally support students and any factors that may influence this. We used concepts from scaffolding theory to analyze the support. By organizing the data into segments based on these scaffolding concepts, we were able to characterize the different approaches taken by the teachers. The types of support varied; for example, the teacher might take control of the process or stimulate the students’ reasoning. The support appears to be adapted to the students, the lessons and the topics of the conversations. These are possible factors that may influence the way in which teachers support the students during design activities.

Design activities are gaining interest as rich contexts for learning science, technology, engineering, and mathematics (STEM) subjects. STEM teachers may find this challenging however, as designing requires support that they are not used to providing. In a subject like chemistry, teachers would have to balance creativity and responsibility for the students with concept learning and safety in the classroom. In a case study, we analyzed the verbal interactions of three teachers with their students during design activities in the classroom, with the aim of understanding what teachers and students talk about and how chemistry teachers support the students with their designs. During the lesson, students worked on the design of a self-heating or self-cooling cup, while also performing chemistry experiments to learn about the energy effects of reactions. Such a lesson reflects what design activities in the chemistry classroom could look like. We described the topics that teachers and students talk about, revealing that teachers support students through several types of feedback and questions. We also found that teachers support design tasks in a more open, constructive, and encouraging way than is used for experiments and chemistry concepts, which are supported in a closed, clarifying, and steering manner.