Computing Education Research (CER) is an example of Discipline-Based Education Research (DBER) that has developed substantively over the last few decades. This is especially true for the Uppsala Computing Education Research Group (UpCERG). In this paper, we use UpCERG as a lens to see how a conscious use of theory can enhance the quality of STEM education. This is accomplished through presenting our use of the concept 'theory' in the paper and by using the theses produced by the group as a way to illustrate the increased importance of theoretical development.