While it is widely believed that Specialized Content Knowledge (SCK) is essential to effective and quality mathematics teaching, the specific constructs that compose SCK remain underspecified. This paper describes the development and use of a new framework that extends the notion of SCK. The framework was trialled with a cohort of 90 first year Bachelor of Education (Primary) pre-service teachers who enrolled in a regional Australian university. The pre-service teachers undertook a mathematics test, which required them to address school students' misconceptions and to explain specific mathematical concepts. Resultant data (i.e., the pre-service teachers' responses to the written test) provided an empirical basis for the proposed constructs of SCK. The analysis of the data allowed insight into the central question: whether the proposed framework enables researchers to identify the constructs of SCK in the pre-service teachers' responses to a written test which examines their SCK. Ultimately, we aim to conceptualise the constructs of SCK through elaborating the theoretical and empirical basis.