It seems that everyone is talking about improving education. Indeed, over the past decade, governments have invested more in education in an effort to improve the quality of primary and secondary schools. Has this investment paid off? In every PISA cycle since 2000, students and school principals were asked a series of questions relating to their schools' learning environment--from the adequacy of educational resources and physical infrastructure to the quality of teacher-student relations. By comparing these self-reports over time, PISA can assess whether, and to what extent, the growing concern about, and greater investment in, the quality of education has led to real improvements in schooling. Findings highlighted in this edition of "PISA in Focus" include: (1) The quantity and quality of resources available to schools improved significantly between 2003 and 2012, on average across OECD countries. Greater financial investments in education provided schools with better teaching staff, instructional materials and physical infrastructure; (2) The learning environment in schools across OECD countries improved between 2003 and 2012, particularly when it comes to teacher-student relations and the proportion of students who arrive late for school; and (3) The degree to which students from different socio-economic backgrounds attend the same school did not change between 2003 and 2012, while students with different academic abilities and needs were less likely to attend the same school in 2012 than in 2003, on average across OECD countries.