This paper reviews literature on constructivist learning theories relevant to and evident in teacher education in a New Zealand university. These theories are illustrated within an authentic technology education context which involves students from a primary teacher-education degree programme. It investigates how a practical activity, based on constructivist principles, successfully leads to the development of student teachers' understandings of technology education and technological practice within an initial teacher education programme. The paper describes the practical activity undertaken by final year students where a collaborative "company approach" strategy is used. The data shows that while undertaking a constructivist based activity, students gain a rich understanding of theory related to technological practice and relevant links to learning in the classroom. Examples are presented of the higher level thinking obtained by the students as they participate in this collaborative and cooperative exercise and reflect on their learning. (Contains 3 figures and 1 table.)