Over the past 20 years there have been numerous calls in Australia and beyond for extensive educational reforms to preservice teacher education in the sciences. Recommendations for science teacher education programs to integrate curriculum, instruction and assessment are at the forefront of such reforms. In this paper, we describe our scholarly action-research approach to the teaching of science and science-method subjects to Australian preservice primary-school teachers in the state of New South Wales. We present an interactive educational design model founded on a solid theoretical literature base that incorporates Pedagogical Content Knowledge as an integrative mediating framework and which drives students' interactions with the elements of the design model. The results from our mixed-methods study suggest that the approaches adopted through two extended vignettes show significant increases in preservice teachers' competence and confidence. Together, the qualitative and extensive quantitative data suggest participants obtain a newly developed sense of enthusiasm for science and an understanding of the role that it can play in the primary- school curriculum. The data provide strong evidence that the approaches being called for in some of the earlier reforms and most recently by Bybee (2014) are effective.