We received considerable press and media publicity about the shocking statistic that 1 million adults in the UK had very serious problems with reading and writing. This helped to create the impetus for the On the Move campaign led by the BBC in the mid-1970s.

Our research - if you could call it that - was based on an extrapolation of surveys undertaken every four years since the end of the war among school-leavers. My guess is that it was not very reliable but was the best available at the time.

Subsequently, more research was undertaken, much of it by my own agency.

All of this suggested that our 1m was a serious underestimate. This later research was rather more reliable because most of it was based on testing the literacy (and later numeracy) skills of samples of adults. Most of these surveys were reasonably consistent and suggested that around 15 per cent of adults had problems.

In 1997, the Organisation for Economic Co-operation and Development (OECD) carried out an International Adult Literacy survey (IALs) involving research in a number of industrialised countries. It indicated that about 23 per cent of our adults had problems with literacy and numeracy. In fact, we came almost bottom of the IALs league table. More than 20 years or so, the number of adults with inadequate basic skills has increased from 1m to 7m.

This shock-horror statistic informed the work of the group led by Sir Claus Moser (now Lord Moser), though it is fair to say that there were considerable doubts about the reliability of the IALs research at the time.

Furthermore the research never made it clear whether there were 7m adults with literacy problems and an additional 7m adults with numeracy problems or whether some of these, as is likely, were the same people.

So did we have 7m adults with poor basic skills, or 14m? The press release for the latest research published by the Department for Education and Skills suggests that the number of adults with literacy problems “has fallen from the 7m estimated in 1997 to 5.2m adults now”.

If so, it is tremendous news. After increasing from 1m to 7m in the 1970s, 1980s and 1990s, there has now been a not inconsiderable reduction of 1.8m.

But this is a claim that cannot be substantiated. All the recent research indicates is that earlier research was flawed, because there’s little evidence that 1.8m adults have joined basic skills programmes and improved their literacy to the extent that they are no longer in the poor-literacy group.

According to the same press release, the number of adults with poor numeracy has fallen only “slightly from the 7m estimated in 1997 to 6.8m now”. (That appears to be based on the assumption that in 1997 there were 7m adults with literacy problems and 7m with numeracy problems.) This most recent research also throws up some interesting, if confusing, information. For example, it suggests that 30 per cent of people with degrees have literacy levels lower than that required for grades A*-C at GCSE. That is good news for all of those who think that degrees are given away by return of post.

It suggests, contrary to almost all earlier surveys, that more young adults have poor basic skills than middle-aged people. This does not sit comfortably for ministers with improving standards in schools, and the OECD’s Programme for International Student Assessment study in 2000 that suggested that our 15-year-olds “achieved a high position” in literacy in relation to other countries.

Even more worrying, only 2 per cent of those in the survey felt that their weak skills had hindered their job prospects or led to mistakes at work. So we think that they have a problem but they do not.

What does all this mean? I believe that we need to get a reliable research method for estimating educational attainment that is robust over time, perhaps through establishing a specific institute with responsibility for all future research from cradle to grave. Without reliable and accurate information, too much research is about spin rather than substance.

Alan Wells is director of the Basic Skills Agency