The success of Finnish students in PISA has been a great joy but at the same time a somewhat puzzling experience to all those responsible for and making decisions about education in Finland. At a single stroke, PISA has transformed our conceptions of the quality of the work done at our comprehensive school and of the foundations it has laid for Finland's future education and development of knowledge.

Thanks to PISA, Finnish schools and school practices have suddenly been brought into the focus of international attention. Why are Finnish students performing so well? What is the secret behind the Finnish success?

In this publication, we as the researchers responsible for the implementation of PISA in Finland, try to open up some perspectives on the possible reasons underlying the high performance of Finnish students in PISA. There is, in fact, no one single explanation for the result. Rather, the successful performance of Finnish students seems to be attributable to a web of interrelated factors having to do with comprehensive pedagogy, students' own interests and leisure activities, the structure of the education system, teacher education, school practices and, in the end, Finnish culture. Perspectives on this web of explanations will be opened up not only by analysing the results of PISA but also by considering some characteristics of the Finnish education system and our cultural heritage which, both at and outside school, can be thought to have contributed to Finlands successful performance.