Purpose: Whilst beneficial, the use of evidence to improve teaching and learning in schools is proving difficult to achieve in practice. The purpose of this paper is to shed new light on this issue by examining the applicability of a model of rational behaviour as relates to the notion of evidence-informed practice (EIP). Specifically, exploring the question: "if EIP is rational behavior, why are not all teachers engaged in it?", the authors examine whether the beliefs and perspectives of teachers in relation to EIP, align with their evidence-use behaviours. The authors then assess what factors prevent teachers/schools from engaging in EIP. Design/methodology/approach: To examine beliefs, instances of, and barriers to evidence use, the authors employ a Gradient Boosted Tree predictive model to analyse data from a survey of 696 practitioners in 79 schools. Findings: The findings suggest that, should they wish to increase EIP within their schools, school leaders need to: first, promote the vision for evidence-use (i.e. actively encourage its use); second, illustrate how research and evidence can be effectively employed to enhance aspects of teaching and learning; and third, establish effective learning environments, in which learning conversations around the use of evidence, can flourish. Originality/value: Using a new, innovative model of rationality, the authors conclude that despite the focus on EIP in many school systems world-wide, evidence use will never be meaningfully realized unless school leaders prioritize EIP as a school commitment. Simultaneously, given the high-stakes accountability environments facing many school systems it is unlikely that prioritization of EIP will occur until EIP forms part of any education system's accountability regime.