In some ways, it's a teacher's dream. If your pupils skive you can dock their wages . If they misbehave you can order extra detention. And if you lack the charisma to hold a normal class spellbound, here you have, in the most literal sense, a captive audience.
There are advantages for those captives too. They earn Pounds 6 a week for coming to classes. They escape some of the more tedious prison chores. And the enforced leisure of Her Majesty's pleasure gives them ample time to master new skills.
At Ford Open Prison, I met inmates who were making the very most of this opportunity. One prisoner of nearly 30 years had discovered an artistic talent that has transformed his life. Another spends his time juggling studies in three languages. And I met teachers who, far from coasting on an easy ride of enforced class discipline, were responding imaginatively to a challenge and finding in the process a rare job satisfaction.
Ford is for low security Category D inmates. Security at the main gate is obvious but not oppressive. Wide open spaces separate low rise buildings, and most prisoners live in single rooms rather then cells.
Yet it's still a prison. Dick New, acting education officer, locks his office door behind him - but feels the need to explain his action. "Well, there are criminals here!" he says. And if you're a visitor wanting to use the toilet, you must ask for a key.
Ford is a working prison, and education counts as a work option. Learn your lessons and you'll earn the standard pay of Pounds 6 a week. Every inmate is assessed by education staff when he arrives: some choose to grow vegetables; some to make and mend; some to learn.
The classrooms in the eight-year-old education block have survived annual budget cuts to remain calm, hardworking places. "We have few discipline problems," says Dick. And that's hardly surprising since the students know there are some very real sanctions - from docking pay to extra days added to sentences.
Dick leads a team of two full-time and 14 part-time tutors, all employed not by the prison but under contract from Northbrook College in Worthing, West Sussex. The prison governor is the ultimate authority but chooses to give Dick a relatively free hand.
He organises classes in three strands. In the mornings some 60 inmates take the main courses to which they have been guided by the staff. These include basic skills - 15 per cent of Ford inmates have problems with basic literacy - catering, visual arts, office administration and small business start-up.
After lunch there are optional courses, and in the evenings, classes for any inmate to attend. Currently the most popular is on making soft toys. "It's an opportunity for them to make something for their children," explains Dick.
As well as the full-time courses, there is a group called Open and Flexible Learning which brings together inmates who are studying independently, often with distance learning providers such as the Open University, or with the aid of books or language cassettes.
Classes start at 8.30, with the midday break at 11.45. Lunch lasts 1 hour 45 minutes - "it can take a very long time to get 500 men through the dining hall," explains Dick. The afternoon session then runs from 1.30 to 4.30. But the turnover of 40 prisoners a week also means that courses must be tailored to start and finish at any point.
Arriving at Ford, I had a sneaking feeling that a spell in jail might be a real chance for the more academically-minded to devote endless, concentrated hours to something difficult - to learn Mandarin Chinese or to read Ulysees. It was not, I discovered, an entirely misguided view.
I met Thomas, a young man with a public school background, who clearly feels it important not to be swamped by the disastrous turn his life has taken. "It would be so easy to waste it and regard it as a loss. I feel it can be turned into something positive, and that the best way is to use the time in learning something new."
That's why Thomas is learning French, Arabic and Russian. There is a taught course in French, and for the other two languages he uses commercial packages provided for him by the education department. He studies for most of the day in a way that he believes would not be possible among the distractions of life on the outside. "I do perhaps an hour-and-a-half in one language, take a break then come back and hit another language."
Terry is also a language student, learning Spanish in the same group. "A spell in prison is a great opportunity to re-appraise your life," he said, "Ithough I wouldn't recommend it as a sabbatical."
Equally diligent is Bas, now serving the 29th year of a life sentence. When he came to Ford two years ago the art tutors discovered his largely latent artistic talent - and changed his life. "They managed to free me up," he says. "I paint mainly violent seascapes bordering on the abstract. Now painting is not just part of my life, it is my life. I'm eternally grateful for what the tutors have done for me."
The gratitude goes both ways, as I found when the artist's teacher, Barbara Johnson, described the satisfaction she gets from working with prisoners. "A lot of them have never painted or drawn before and are really excited when they find they can do it."
Artistic ambitions aside, the main thrust of the work is always directed towards improving the life chances of inmates when released. Hence the business start-up course which began in response to requests from inmates and helps men who want to be self-employed.
The basic skills programme aims at improving literacy and numeracy with an individual learning plan for each student. Typically, the young men who need help with reading and number have done badly at school. Danny told me he had been ignored.
"The teachers took more notice of the ones who were doing well. But I've learned quite a lot since I came here in February. There's individual attention when you need it."
Some inmates get the chance to attend college courses in nearby towns - Terry did some of his Spanish in this way and there is a great demand for a forklift truck driving at one local colleges. But these outside opportunities are severely budget-rationed, and Dick has the difficult task of deciding who should go. Cuts have not hit Ford as hard as some other prisons, but a popular music course has just been axed, and the education materials budget cut by more than a third.
Dick has no regrets after coming to Ford eight years ago following several years as a secondary school art and pottery teacher. "Most teachers in prison education tend to stick with it. It isn't a dynamic career, but it's very worthwhile."
He talks of "seeing people whose experience of education has always been negative rediscovering the thrill of achieving and learning" and of "the satisfaction of helping to rebuild lives which have been destroyed".
A lot of Dick's time is spent just talking to men - advising, counselling, reassuring them and, inevitably, turning down unreasonable or impractical demands. It is clearly one of those jobs which, like so many in education, demands that you go that extra mile.
Now, though, prison education is subject to competitive tender, and Dick believes positive attitudes will be damaged as a result. In less then two years, time the contract to supply education to Ford comes up for renewal. Dick hopes that Northbrook will win it again but there is no certainty.
The effect, he believes "has been to undermine the sense of loyalty prison education staff have had for many years. It seems a folly to contemplate discarding years of experience on the grounds of cost".