The apparent upturn in the United States’ educational fortunes is one of the most interesting developments identified by the TIMSS research.

The US government has invited ridicule by saying that it wanted American children to be the best in the world in maths and science by the year 2000. But this study shows that it was not a completely foolish ambition.

The US may still be struggling in the educational wake of the Tiger economies, but it appears to be gaining some ground - no mean achievement for a country with a very heterogeneous population and a large “underclass”.

It is true that the test items were, in some respects, more familiar to children in the US than they were to pupils in other countries. Primary curricula are broad in the US, but this is invariably seen as a weakness rather than a strength. One critic, William Schmidt of the US National Research Centre, has complained that schools’ curricula are “a mile wide and an inch deep” (TES, April 4).

In maths, 9 per cent of US children were placed in the top 10 per cent internationally - 2 per cent more than the English and Canadians - and 56 per cent were in the top half of the performance range. Hungary, which is regarded as one of Europe’s strongest mathematical performers, achieved the same score.

The overall mean scores also suggest that the US has overtaken England and Scotland in maths - at least at age nine - and its children did well in the TIMSS science tests.

But academics such as Professor David Berliner of Arizona State University argue that national averages and international rankings do not provide an illuminating picture of US education.

It would be more accurate to say that public school children in states such as Iowa, South Dakota and Minnesota are the equal of pupils in Asian nations whereas poor children in general, and Hispanic and African-Caribbean pupils in particular, are way behind the Pacific Rim, he says.

His argument is borne out by a TIMSS sub-study that involved public schools in 20 predominantly wealthy and white districts on the North Shore of Chicago. The relatively well-resourced schools asked to take part in the TIMSS testing after a University of Michigan psychologist, Harold Stevenson, claimed that no school in the Chicago area was anywhere near as good as Japanese schools he had studied. They proved him wrong.

In maths, only one of the participating nations was significantly ahead of them, and in science they equalled the best in the world.

In Berliner’s opinion, therefore, the most effective way of pushing the US further up the rankings would be to tackle family poverty, and inject additional funding into disadvantaged neighbourhoods and school districts.

His view is shared by another US academic, Lawrence Stedman, an associate professor at the State University of New York. He thinks that national averages should be retained, but adds: “In future, assessments should routinely disaggregate results by race, region, language and family background. No doubt we will find striking differences in the achievement of different social classes and minority groups within each country.”

He says each country because he believes that the performance of pupils in Pacific Rim nations is less uniform than is commonly supposed. One of the surprising - but still generally unknown - findings of the International Assessment of Educational Progress study in 1991 was that American 13-year-olds’ maths performance varied less than Taiwan’s.