Only 20 students had had private tuition in English and there was very little impact on GCSE grades.

Professor Ireson said: "Most parents find a tutor through word of mouth and it can be difficult to find a good one. Our results suggest that tutors are not helping girls as much as boys at this level."

Cultural differences

The study of potential links between private tuition and exam results was part of a wider study by the Institute of Education involving 3,500 pupils in England. Selected early findings from the study were presented to a conference in the autumn.

These included the suggestion that just over one in four (27%) children were being privately tutored.

E-mails to the BBC's news website suggested people were paying between £15 and £25 a session.

Bill Fleming is the director of the Top Tutors agency, which has been supplying tutors in the south east of England for 20 years.

"I can't comment on the results achieved because once we have placed a tutor with a family we do not often hear how a student gets on in their exams," he said.

"But many people do find the extra tuition worthwhile. Students can mention particular problems, go over past papers or might find it easier to ask questions in a one-to-one setting."

Confidence boost

Parent Anya Rowson, from London, told the BBC News Website both of her children had benefited from private tuition.

"They have used this time to revisit subjects that have not been understood during the school timetable. Private tuition has significantly helped both of them.

"It has also increased their confidence in the classroom, as they are no longer afraid to raise their hand in class, for fear of always being wrong.

"I certainly do not feel that I have wasted my money. In fact I am indebted to the tutors for all that they have done."

Aspirations

The wider research found children from middle-class or professional backgrounds were most likely to have extra tuition.

One in three (36%) students whose fathers held senior and professional positions reported that they had had a tutor, compared with one in 10 (11%) whose fathers were in unskilled work.

Ethnic minority families were also more likely to employ tutors than white families. Almost half the Indian students (45%) had had tutors at some point, and one in three Chinese and African students (35% and 31% respectively).

This compares with a quarter of white European students and one in five Bangladeshi students.

Professor Ireson said: "Parents who have benefited from higher education themselves may have higher aspirations for their children and be more able to pay for extra support.

"Cultural factors also affect whether young people have private tuition - in some countries, such as India, tutoring is the norm."

We asked for your comments on this subject.

Below are a representative selection of the comments we received:

My parent paid for extra tuition for my maths GCSE. I've never been good at maths. In my mocks I got an "F" as my maths mark, which prompted my parents to ask a teacher from my school to give me extra tuition. They paid him £15 for a one hour lesson which I had once a week and I'm very glad to say that it worked! I even got a higher mark in my non-calculator paper than I did in the calculator paper, and came out with a "C" grade.
Sam, Cumbria, UK

I had chemistry tuition at O and A-level and it made a big difference back in the 80s. My chemistry teacher was a poor teacher and while I still found it boring the tuition turned a probably fail into grades similar to my other subjects A (O level) and B (A level). As a postgraduate I tutored GCSE Maths and Physics and conclude from that experience that the result really depends on the child and the parents. Some kids are really keen, others don't care and never do the homework you set. The best parents find a quite space for the child to study with you and ask lots of questions at the end of each session. The not so good ones plonk you in the kitchen and never ask questions afterwards. My parents took great interest in my education and asked lots of questions. When reading this kind of report one must make sure one is comparing like with like. A disinterested kid with disinterested parents isn't going to benefit from tuition.
Roger, London

Whilst studying for my PhD I gave mathematics tuition to a number of students studying from GCSE to degree level. The problem was often not a lack of ability or good teaching but a lack of motivation. Simply hiring a private tutor can in itself be very de-motivating. Families should consider carefully how best to support the work of the school, money isn't always the answer.
Ray Lashley, Bristol, UK

My experience of 30 years ago is that children who were give extra tuition to get through particular exams may do better than predicted in these exams but this improved performance would not be maintained in subsequent courses.
Steve Howie, Cambridge, UK

Back in 1998, when my daughter was nine, she came home from school one day and asked my husband and myself, why none of the black kids in her class could read and the only one who could read had a Chinese mother. The next morning, I went to her school, to confirm if this was true. To our dismay, her observation was true.

It was very clear to us that something was wrong somewhere. The education system was failing my daughter. We had no choice but to do something about it.

All through their education, both in junior and secondary school, we have had to pay for private tuition.

I disagree that private tuition does not help. I saw the difference it made to my children's education. My family and friends and a lot of the other parents from the ethnic minority, I am sure, will disagree with the results of this research.
Mrs Adeyemi, Milton Keynes

I am a director of a UK-wide tuition agency. I was also a tutor for many years. We tutor thousands of students a year and to say that no benefit is achieved from tuition is blatant and illogical nonsense. It also implies parents are stupid - after all who would continue paying for lessons each week when the child is supposedly not gaining any benefit? What does the student say in all this time?
Clive West, UK

My son was dyslexic and at age eight his teachers admitted defeat. I took him to private tutors after that. By the time of his secondary education and after a teacher had told me that dyslexia was a "white middle class disease", I was using tutors quite extensively. My son is now a PHd final year student at a top London university and without doubt we have his wonderful tutors to thank for this.

They offered us one to one, and more importantly eye contact. His school teachers never did either of these. They offered me human interaction and made me feel as if I was a mother and not a "parent" - a most derogatory term I have discovered, in use in the staff room. They offered my son a life and a chance in the work place which his teachers did not. I am English and a single parent and my son's tutors were not cheap but most necessary. Add this to your statistics.
Sue Young, London

My parents went that one step further and actually home educated myself, my brother and my two sisters. Home tuition certainly didn't harm us academically (we all have university degrees). It was a huge sacrifice for them though, as my mum gave up work to teach us (she was previously a school teacher).

I would think that the amount of success of private tuition is therefore somewhat proportional to the amount of effort put in by both student and tutor.

Certainly one aspect that could potentially be tutored better at home are the more personal aspects of learning, such as learning skills and initiative.
Dan Matthews, Oxfordshire

I am of African origin born in the UK with a senior professional background. The media has recently publicized that black afro-Caribbean boys in particular, are failing to achieve academically. It is therefore little wonder that black parents seek further educational support for their children. Classes in primary schools are far too large.

My son is in the top 5 in his year in maths in a good R.C school, however I do use extra tuition for literacy to support him to be the best that he can be and improve his chances for university and employment. From my perspective extra tuition works for us!
Adwoa Odoso, London

I would disagree, I had extra out of school lessons in maths and it helped me no end. If it was for the extra lessons I would have never made the grade and would have not managed to get to college and university
James, Cambs

Whilst studying for my PhD I gave mathematics tuition to a number of students studying from GCSE to degree level. The problem was often not a lack of ability or good teaching but a lack of motivation. Simply hiring a private tutor can in itself be very de-motivating. Families should consider carefully how best to support the work of the school, money isn't always the answer.
Ray Lashley, Bristol, UK

My daughter was becoming increasingly frustrated in her German lessons, wanting more than was delivered. We took the step of using a private tutor once a week and believe that this was responsible for her A* grade at GCSE. Thoroughly a worthwhile exercise however, why did we have to resort to it?
Lucy Reeves, Worcester

I attend a top performing single sex grammar school, but I found I was being let down by my French grades at GCSE level. My parents paid for a personal tutor, and it paid off, my predicted grade was a C, and I achieved an A.

However, at AS-level with maths, I once again had a tutor, however, this time round I got a U.

I feel it depends very much on the tutor qualifications, and how adapt there teaching knowledge is. It wasn't until we parted ways that I realised my maths tutor had never actually taught in a classroom!