US school children regularly score lower in science and math tests than school children in some other countries. These test results have been the source of much hand-wringing and have prompted calls for spending more money on k-12 education. But what do such scores really mean? Compared to many other countries, the US has a heterogenous population of different languages and a greater diversity in the lower classes. In my Southern California city, over 100 languages and dialects are spoken in the public school. Other countries have more homogeneous populations--think Japan, Korea, China, for instance. In addition, we have a black school subculture, with some level of acceptance, that scorns academic achievement and pressures black children, especially boys, to turn away from book learning. If we parse the American school test scores, separating out the results by children of non-English speaking parents, pulling out the results of immigrants in the country less that five years, and isolating black boy's scores, I am sure the remaining test scores would be higher and more in line with the higher foreign school scores. Anyone know of research that does such analysis?