"When this client group is seen as being of greatest importance, the college may direct its energy and creativity to recruit them and develop curricula to meet their particular needs at the expense of similar innovation for adult students," it says.
Although many colleges are actively targeting adult learners, the review group which carried out the survey found that some material, such as application forms that requested parents' signatures and "a satisfactory reference from your school", seemed to be aimed exclusively at school leavers.
The greatest trend away from school-leavers is in Scotland. For example, at Glasgow College of Food Technology, 45 per cent of students are over 25. England and Wales are well behind. Better and more childcare provision, outreach centres, community involvement, student guidance and staff training were all identified as crucial in attracting adults.
"The breadth and depth of the curriculum offer made to adult students still depends very much on each college's tradition pre-1992, although a number of institutions which were primarily for 16 to 19-year-olds have begun to open up to adult learners," the report concluded.
Alan Tuckett, director of NIACE, said that over-25s tended to be overlooked because they often studied part time or for short periods: "Adults represent an important market to colleges needing to achieve 26 per cent growth inside the next three years.
"We have to win the the case for adult education, institution by institution and principal by principal. The real difficulty with adult provision is that it often involves colleges spending money just to put their toe in and test the water." But, he argues, getting colleges to commit themselves to course provision is only half the battle.
"The biggest challenge is in persuading people that they want to learn and we have got an awfully long way to go with that."
Although an estimated six million adults pursue some form of further education, mature students are twice as likely to come from social class AB than DE and three times more likely to have studied in the last three years if their initial education lasted beyond the age of 18. Successive studies have shown that unless specific groups in society are targeted, then adult recruitment to colleges will tend to be confined to middle-class students who already have a good level of education.
Now, however, many colleges are challenging this pattern and trying to reach sectors of society which might not normally enrol for college courses. The range and provision of such initiatives varies widely, but the signs are encouraging.
In the West Country, Devon and Cornwall TEC has just begun a "Learning for Life" campaign. It's a collaborative venture, bringing together 16 educational institutions in the West Country, with the objective of attracting people into post-16 education and challenging the perception that education begins and ends at school. The TEC estimates that through mass leafleting and television and press advertising, the three-month campaign will reach 82 per cent of all adults in the region. A special feature of the campaign is an awards programme for over 50s, a group which is traditionally under-represented on college campuses.
Sheffield College, the biggest FE institution in Europe, promises a "New Deal for Adults", a range of vocational training courses open to the low-paid and unemployed. A special feature of the scheme, according to the college's adult strategies officer, Liz Cousins, is its tutorial base which allows students to share experiences and support each other.
Sheffield is planning a "Fresh Start" for September which builds on the lessons learned from the New Deal for Adults programme and a popular 13-week taster course which attracted 120 students last year.
The college's literacy campaign, which employs local people under the guidance of college staff to teach English in their communities, has been running since the late Eighties. "They could be teaching their uncles or aunts or next door neighbours," says college principal Alan Chapman.
In Glasgow, Langside College gives adults in deprived parts of the city a "Second Chance to Learn" through writers' workshops and classes in current affairs and local history, which take place in community centres for two half days a week. Course co-ordinator Ian MacPherson estimates that 70 per cent of the students, most of whom come with little or no formal qualifications, go on to further study.
Wandsworth Adult College acts as a feeder route for students to progress on to courses at the neighbouring, and affiliated, South Thames College. Courses include "family workshops" where mothers and children work alongside each other, and several non certificated courses which build on skills such as dressmaking and childcare which students bring with them.
In Wales, Gwent Tertiary College collaborates with the Workers Educational Association and other agencies to offer courses to around 12,000 adult learners. A scheme for young mothers on a Pontypool housing estate to learn basic IT skills is typical of their outreach work. "These projects might start in a variety of ways - through social services or a health clinic, for example," says Katy Burns, adult education co-ordinator in the region.
"Colleges are still seen as intimidating places by a lot of people and it can be a long, slow path to get people through their doors. So what we are trying to do is to get them doing something that sparks their enthusiam. "