The three teaching interventions described in Chapter 4 were designed to address two overarching aims. The first of these was to develop students’ conceptual understanding in specific topic areas so that the learning outcomes were measurably better than those achieved by students following their school’s usual scheme of work. The second aim was for the teaching interventions to be usable by teachers not involved in their development, leading to similar enhanced learning gains (with minimal training). This second aim, it seems to us, is central to any

argument that a teaching approach should be more generally adopted: there has to be some evidence that the positive effects of the teaching approach can be transferred from the site of development. Our evaluation of the teaching interventions therefore addressed the following questions:

• Did students who were taught using the designed teaching interventions develop conceptual understanding that was consistent with the aims of the teaching? Did students achieve measurably better conceptual understanding than comparable students following their school’s usual scheme of work? Were there any differences in learning outcomes for students taught by teachers who had been involved in the design of the teaching (the Development Phase teachers) and those who had not (the Transfer Phase teachers)?