In this study we measured the impact of a professional development model that included directive coaching on the instructional practices of Western Australian primary school teachers taking up explicit instruction. We developed and validated protocols that enabled us to measure teachers' fidelity to the salient elements of explicit instruction and interviewed participants about the impact of the coaching program on student learning, their feelings of self-efficacy and attitudes to being coached. Numerical scores to indicate teachers' demonstration of explicit instruction lesson design and delivery components changed positively over the five observed lessons and directive coaching had a positive impact on teachers' competence and confidence. The elements of the coaching process that the teachers found valuable were the coach's positive tone, the detailed written feedback, and the specificity, directness and limited number of the suggestions. Implications for schools with reform-based agendas wanting to change teachers' instructional practices through instructional coaching are discussed.