The Programme for International Student Assessment (PISA) index of teacher support was derived from students’ reports on the frequency with which: the teacher shows an interest in every student’s learning; the teacher gives students an opportunity to express opinions; the teacher helps students with their work; the teacher continues teaching until the students understand; the teacher does a lot to help students; and, the teacher helps students with their learning. A four-point scale with the response categories ‘never’, ‘some lessons’, ‘most lessons’ and ‘every lesson’ was used. The index was derived using the WARM estimator (Warm, 1985).