The reforms vary across countries, as they are influenced by context, traditions, institutional settings and specific national and regional challenges. These policies all aim to improve the quality of schools and instruction and have been grouped according to the different policy options and their scope. A majority of 15-year-olds across OECD countries find that their classrooms are conducive to learning, but there are challenges across schools in some countries, including lack of student motivation, lack of relevant curriculum, difficulties in attracting and retaining qualified staff, lack of teacher collaboration and lack of professionalisation of school leadership.