Whilst beneficial, the regular use of evidence to inform teaching practice (evidence informed practice -- EIP) has proven difficult to achieve. To shed new light, we pose the question: 'if EIP is rational behavior, why aren't all teachers engaged in it?' Correspondingly, we examine whether the EIP beliefs and perspectives of teachers, align with their evidence-use behaviours. We then assess what factors prevent teachers/schools who wish to engage in EIP from doing so. Employing a "Gradient Boosted Tree" predictive model to analyse data from 696 practitioners in 79 schools, our findings suggest that, to increase EIP within schools, school-leaders need to: (1) promote the vision for evidence-use; (2) illustrate how EIP can be used effectively; and (3) establish effective learning environments.