These findings are obtained after adjustments for levels of economic development across countries, student background characteristics, and features of national school systems. (educationnext.org)
National school systems already have buildings, trained teachers, and an established curriculum. (gse.harvard.edu)
They come in response to criticism of U.S. math instruction as being far too broad without the kind of indepth instruction practiced in national school systems in Europe and Asia, where students often outperform their U.S. counterparts on tests like the Trends in International Mathematics and Science Study. (gse.harvard.edu)