betweenschool differences account for less than of the oecd average total variation in performance in denmark by contrast across oecd countries of the overall performance differences are observed between schools the performance differences that do exist between schools are relatively closely related to socioeconomic disparities between schools performance differences within schools are around the oecd average but these withinschool differences are more strongly related to students socioeconomic status of the total variation in performance is observed within schools oecd average and of the performance difference can be explained by differences in students socioeconomic status oecd average in the pisa mathematics assessment students with an immigrant background scored an average of points lower than their native peers after accounting for socioeconomic background oecd average points students with an immigrant background in denmark were times more likely to perform in the bottom quarter of the performance distribution than nonimmigrant students oecd average times more likely