On the sidewalk outside the Marriott convention hotel in downtown San Diego, passers-by were reaching into the kerbside newspaper dispensers and pulling out free copies of The Learning Annex, the unintentionally funny magazine that promotes some of the weirdest “continuing education” courses on the planet.

“How to talk to your cat - increase its IQ and learn about cats’

spirituality” - Course fee: $59 (pound;33). “How to paint like Monet in a day - using coloured pencils”. Online fee: $54.

Inside the 1,300-room Marriott, the topics being discussed by 12,000 academicss at the American Educational Research Association conference were rather more serious. Why is there still a frightening gulf in achievement between African-American and white children? How best to recruit and retain teachers in high-poverty inner-city schools? And, perhaps the most difficult question of all: how can research findings be better disseminated and influence policy?

Linda Darling-Hammond from Stanford university finds it easy, but still painful, to answer the racial achievement gap question. “The wealthiest 10 per cent of school districts in the US spend nearly 10 times more than the poorest 10 per cent,” she said.

“Poor and minority students are concentrated in the less well funded schools, most of them in the inner cities. On every tangible measure - from qualified teachers to curriculum offerings - schools serving greater numbers of students of colour have significantly fewer resources. It all adds up.”

Jeanette DiBella, the principal of Providence - St Mel, a successful private school in the most deprived area of Chicago, agreed that adequate resources are vital. “We have to raise $3.5 million (pound;2m) a year just to keep the doors open,” she told the AERA researchers. But her school, which is in the most dangerous neighbourhood in the United States (a body was dumped in the playground last month), has found that other factors are also important. Positive behaviour and high achievement earn lavish praise and - this being the home of capitalism - shares in the McDonald’s hamburger empire.

“My boys tell me they run to school rather than walk, because of the gangs, but all our students still went on to college last year,” she said proudly.

Ms DiBella’s story is, however, as atypical as they get. The US school system is now more segregated than it was 20 years ago and inner-city schools are struggling to attract the high-calibre staff that the Bush administration says all schools must have by 2005-6. Academics queued up to explain why it could not be done and how some of the best minority teachers were being driven out of teaching by the new $70 (pound;40) proficiency tests that some of them are taking, and failing, up to 10 times.

But what can researchers do to help them and their schools - particularly if their findings are ignored by both the media and politicians? Greg Toppo of USA Today, one of the few American daily newspaper journalists to cover the conference, told the researchers that if they wanted to “sell” their studies to the media they had to pass the “parking lot” test. If they could not shout their findings across the lot then journalists would not be interested.

But Professor Karen Seashore Louis of the University of Minnesota said that as some research messages were unpopular there was little point in trying to shout them out to anyone. “Some years ago I told a group of policy-makers that one thing I really knew was that big schools don’t really work for city kids. But the big school was built anyway because the football team wouldn’t have been successful if it was smaller.”

Such personal testimonies are always the most interesting elements of the AERA conference. This year one of the highlights was an elegiac presentation by Nora Donnelly of the University of Limerick, Ireland, on the changes her old rural primary school has witnessed since the 1950s. It was as near to poetry as research presentations get. “In the 1950s we all walked to school, and from the first of May until September we did it barefoot along the old ‘mass paths’,” she said. “On the way, we ate the hawthorn leaves and they tasted like cheese. Now the only person who walks to my old school is the principal.”

In America not even the principal would walk, of course. But the US researchers understood her point. Much has been gained from educational and social “advances”, but a lot has also been lost. Researchers have to carry on tallying up both the profit and loss sides of the balance sheet if we are to measure the true rate of progress.