Now few schools would deny the importance of parental involvement or the positive effect it can have on children's learning. But there is still tremendous variation in the way schools put it into practice, how effective it is, and what parents and teachers really think of it.
Many in the home-school movement are now taking stock, looking hard at what is happening, and trying to correct some of the problems.
In her new book, Parents and Teachers: Power and Participation (Falmer Press, Pounds 12.95), Carol Vincent, research fellow at Warwick University, sets out four possible parental-school relationships - the parent as supporterlearner, the parent as consumer, the independent parent and the parent as participant. This last, in her view, is not only the most desirable, but also the least common.
The supporterlearner relationship is the one that schools most favour. The parent's task is "to support the professionals by assimilating their values and behaviour", and to carry out the functions prescribed by the school. This might mean helping in the classroom - although this is left to the individual teacher's discretion, and is still not welcomed by all - or helping at home, with reading, or with a maths scheme. The success of the latter, however, depends very much on how sensitively the schools present it: lecturing parents about the do's and don'ts of reading with children, for example, can be extremely off-putting for some parents, making them feel devalued.
She argues that the parent is given the role of consumer by much recent Conservative legislation. The Parent's Charter stresses parents' right to a say in the school their children go to (few would now use the word "choice"), and the right to information about a school, including national curriculum test results, performance tables, regular inspection reports, and an annual governors' report. But Vincent says that while the charter may specify the information parents should receive. the information does not necessarily lead to participation, or to a more equal relationship between teachers and parents.
A sizeable proportion of parents reject both these models, and become what she calls "independent parents", who have minimal contact with the school. For some, this may be because they become disaffected - feel, perhaps, that their child is unfairly treated or misunderstood and they withdraw. For others, involvement with the school may be impossible because of poor English, long working hours or lack of childcare.
Parents have too few opportunities, Vincent says, to express their views about their children's schooling and so to become more effective participants. Unlike other European countries, such as Denmark, where parents' associations are consulted on education policy, here they are not legally recognised. Parent-teacher associations tend to focus on fund-raising. Annual governors' meetings, a possible arena for parents' discussions of curriculum or school policy, are usually poorly attended.
So what do parents really want from schools? One of the mistakes often made is to lump parents together as a homogeneous group and fail to take into account their different backgrounds and expectations.
"One has to recognise that not all parents want a chummy, close relationship with schools," says John Bastiani, co-ordinator of the National Home-School Development Group. "But there are many others who would like to be more involved, but don't know how to be, or have had difficult experiences of school in the past. Schools need to persist in trying to find new ways to draw them in."
If parents do not appear regularly, schools should not assume that they are apathetic about their children's education, says Melian Mansfield, executive member of the Campaign for State Education, and a home-school specialist. Many lack confidence, are intimidated by formal situations, or simply have problems getting out in the evenings.
What most parents want above all, she says, is to know what is going on at school: what their children are learning and how they can help them. As one mother at an inner-city school, quoted in Carol Vincent's book, said: "The school should let you get involved. I would like to know more about the teaching. I want to know why they do the things they do."
Children often behave very differently at home and at school, and parents and teachers need to find ways of pooling their knowledge, to bring the best out of the child. Another parent said to Vincent: "They may read better at home when they don't feel pressurised; they may know lots of things the school doesn't even have on the curriculum. I think the problem is getting those bits of your child into the school picture."
The difficulty is often on both sides: while parents may lack confidence and feel they are not being let in, teachers, too, may be hesitant and unsure about how best to work with parents. They are not trained for it, although campaigners like Melian Mansfield insist they should be. It is time-consuming, and many still have not accepted it as part of their role.
Home-school contracts do little to bridge the gulf, according to John Bastiani, if parents and teachers simply see them as a means of "bringing the other side into line". But they can be more productive if taken as an opportunity for on-going, three-way discussions between parents, teachers, and pupils, on issues like behaviour, bullying, drugs and homework. And more regular meetings could be arranged between parents and class teachers. Teachers need to establish a one-to-one dialogue with parents of children starting school, to discover in what ways parents can help, what their particular skills are, and what they want to know.
Annual governors' meetings are frequently a missed opportunity for parents to talk collectively about what really concerns them. Refreshments, displays of pupils' work and even short musical performances can make this event more attractive.
Letters sent home to parents could often be written in a friendlier, less directive and jargon-free style. Telling children what the letters are about, or getting them to write their names on them, can help attach more interest and importance to the letters when they arrive home. Parent-teacher associations could extend their activities: organising social evenings for parents, teachers and governors; support groups for parents wanting to talk through particular problems and opportunities for parents to share their skills and interests with the school.
A parents' room in the school can be helpful. So, too, can appointing a member of staff to co-ordinate home-school links, provided that this work is well supported by the rest of the school and does not become marginalised.
Furthering links with the local community - through libraries, secondary schools, local newspapers, businesses, or by giving space in school to a group for the elderly, or parents and toddlers - can make it easier and less intimidating for parents to get involved with the school.
The extent and the effectiveness of this type of work, is at present, extremely patchy. But many schools are finding imaginative and innovative ways of collaborating with parents, often by giving parents a chance to learn something, too.
As part of a two-year project backed by the Royal Society of Arts, Fitzharrys School and its feeder primary, Rush Common County Primary School, in Abingdon, Oxfordshire, have tried to sustain parental involvement during the transition to secondary school. A club for 10 to 12-year-olds, has organised events to introduce children and their parents, from the top primary year, to those in the first year at Fitzharrys. There have also been very successful evening workshops so parents and children can learn and have fun together.
Harbinger Primary School, in Tower Hamlets, east London, ran a video-making project for parents and children with part-time help from a maths lecturer. Children made videos of school dinners, a maths project, and a residential study centre in Essex, to illuminate aspects of school life for their parents.
Parents then made a video, now loaned to other parents, of the school's early-years unit, to help soothe fears over the integration of nursery and classes; parents thus learnt about the unit at the same time as filming it, and were then able to pass this knowledge on to other parents.
Cathy Howell, a parent-education worker in Devon, is currently working with five primary schools in north Devon. Courses she runs for parents include one on how children learn to read, and an induction course for parents whose children are about to start school, consisting of 10 sessions and attended by all parents, to help them to prepare their children.
"This sends the message to parents that they are really wanted: that they are part of the school community and that the school wants them to be part of it. The courses are accredited, too: parents like an accreditation at the end of a course, and it can be useful for them at work."