Resources include human resources, material resources and financial resources and may also consider the amount of time dedicated to instruction. Human resources include, for example, leaders, teachers and their professional development. Material resources include educational materials and physical infrastructure (e.g. classrooms, libraries, school facilities). Financial resources/spending on education covers teacher/staff salaries and other education expenditure, such as building maintenance, transport and other operational costs. Time can include learning time, extra-curricular activities, etc. (adapted from OECD, 2013).