The US schools system is a gargantuan body, controlled by individual states and districts, with barely a guiding hand from Washington, DC. So when the leading schools magazine in America decided to grade the country’s 50 states on their schools, it was undertaking a massive operation.

Education Week produced its 240-page analysis this month in a report titled Quality Counts, funded by a grant from a charitable trust. American schools, it determined, do fairly well in setting academic standard, but show little evidence of achieving them.

They are “riddled with excellence but rife with mediocrity”, and even where they are well funded, they tend to spread the spending unevenly. And the school climate is dismal, said the report.

Quality Counts graded state performances, and the country overall, in six categories: setting standards and assessments, the quality of teaching, school climate, and the adequacy, allocation, and equity of spending levels. It threw in a 2, 500-word summary of each state’s education progress.

The results are not much to boast about. “Some barely get passable grades,and no state can claim a school system adequate to its needs,” said Ronald Wolk, the report’s editor. “These are not exactly report cards that students would rush home to show Mom.”

The year-long study, planned as the first of three, confirmed that the quality of American education for children varies widely according to where they live, their family’s income, and their skin colour.

Some public school districts in New York spend up to #163;8,750 per pupil per year. In parts of poor rural states, however, the figure can be as low as #163;625 a year. New Jersey spends an average of #163;5,062; Mississippi about half that at #163;2,750.

The achievement gap between white and minority pupils, which narrowed in the 1970s and 80s, has, since 1988, begun to widen, evidence suggests. In 12 states there are lawsuits pending challenging the adequacy and efficacy of education for poor and minority students.

One study was cited showing that the percentage of secondary school children who had taken algebra and geometry courses, considered the key to entering college, varied from 35 per cent for black students to 42 per cent of Hispanic and 53 per cent of white students.

In the poorest neighbourhoods, the report said, schools lack not only up-to-date textbooks but even functioning lavatories. School buildings are rapidly deteriorating, with more than a third of children attending schools that should be replaced or need major repairs. Taxpayers are increasingly wary of funding public education.

One of the biggest surprises was West Virginia, historically a byword for redneck attitudes and rural backwardness, which earned three As (as well as three Cs). The sprawling school system of California, predictably, earned two D minuses (and no As).

Overall, American schools did best on setting rigorous educational standards - a B average - though it was more for “effort than results”. They scored lowest on school climate, with an average grade of C minus.

Climate was a combined measure of class size, school safety, parental involvement, and freedom by teachers and heads to make decisions. It was class size that dragged the climate down, said Craig Jerrold, the director of the study.

Academic research in the US has long linked class size to achievement, and now puts the maximum effective class size for elementary schools at 25.But only half of elementary teachers report classes of that size or smaller.

Among secondary schools, moreover, less than half of the English teachers reported seeing fewer than 80 students a day, which is widely considered the maximum number of pupils a single teacher can get to know. Some teach up to 120 or 130 students a day.

Another key factor in assessing school climate was poor classroom safety. In Florida, for example, 58 per cent of secondary teachers thought physical conflicts between pupils were a problem. Nationally, that figure was 40 per cent, up from only 28 per cent in 1988.