This work reports on a Design Based Research study that investigated the development of a module for pre-service science teachers at an Irish university. The module aimed to broaden pre-service science teachers’ views of science teaching, and to extend the types of teaching they experienced as students. Qualitative methods were used to establish the pre-service teachers’ views through the lens of Professional Vision. The Design Experiment consisted of three Design Cycles that were used in successive years. In the first Design Cycle the pre-service science teachers first experienced and then critiqued five workshops in which a number of mostly guided inquiry activities suited for the lower secondary classroom were used. Analysis of this cycle established a first evaluation of Irish pre-service teachers’ Professional Vision. On foot of this analysis Cycles 2 and 3 incorporated a video analysis workshop and a workshop in which participants learned unfamiliar content through inquiry. In Cycle 3, a new analysis framework was developed that combines argumentation, sense-making and transactivity. This framework was used to investigate the type of discourse the preservice teachers engaged in while carrying out an open inquiry activity. Their interpretation of a videotaped class in which a group of lower secondary school students engaged in the same activity was also analysed. The results and conclusions of each of the Design Cycles are used to make recommendations for future directions of the module.