[Excerpt] Another way of evaluating American performance in math and Science is to make comparisons with the upper secondary students of other nations. In the 196Os, the low ranking of American students in such comparisons was defended by citing the fact that higher proportions of American youth took the international test. This is no longer the case. Figures 1 to 4 plot the scores in Algebra, Biology, Chemistry and Physics against proportion of the 18-year old population in the types of courses to which the international test was administered. Where large proportions of the age cohort took the test, lower mean scores tend to result, but this does not explain the poor performance of American high school seniors. In the Second International Math Study, the universe from which the American sample was drawn consisted of high school seniors taking a college preparatory math course. This group represents 13 percent of the age ,cohort, a proportion that is roughly comparable to the 12 percent of Japanese youth who were in their sample frame and is considerably smaller than the 19 percent of youth in the Canadian province of Ontario and the 50 percent of Hungarians who took the test In Algebra, the mean score for this very select group of American students was about equal to the mean score of the much larger group of Hungarians and substantially below the Canadian achievement level (McKnight et al 1987). The median score for the Japanese youth was so high it was surpassed by only 2 or 3 percent of the American students taking the test.