Scenes of parents queuing overnight outside Loreto College in Swords, CoDublin, recently highlighted the issue of school enrolment. Where there are too many students seeking too few places, how do schools decide who gets in and who doesn't?

Recent images of up to 100 parents queuing overnight to secure their child a place at a Dublin school drew attention to the issue of secondary school enrolment policies.

By introducing a "first-come, first-served" policy, the management of Loreto College in Swords, Co Dublin was trying to ensure their enrolment policy was as fair as possible. But the Swords case is not a one-off.

Recently, the Catholic School Parents' Association expressed concern that some schools are using assessment tests to screen children for academic purposes. Others, such as councillor John Ryan of Limerick City Council, have gone further, claiming that some schools are actively discouraging applications from children in disadvantaged areas.

"There is educational apartheid going on in Limerick," he believes. "There are currently 77 children waiting for enrolment to schools in Limerick . . . and those 77 children all come from disadvantaged areas. I feel a number of principals are discriminating. They are receiving applications and are saying they are full, or else they are taking pupils from a wider catchment area," he says.

"The Department of Education and Science (DES) are letting schools get away with cherry-picking . . . it is no coincidence that kids from disadvantaged areas are not getting into schools."

It is important to point out that such policies are against Department. According to a spokeswoman for the Department, schools cannot select pupils on the basis of academic ability. It has been agreed with the three post-primary management bodies that the selection of pupils should be done according to fair and objective entrance criteria, she says.

Schools must disclose their enrolment policy to parents, informing them of the criteria used to select pupils to allay any fears they might have of possible discrimination. Indeed, under Section 29 of the Education Act (1998), parents have the right to appeal a decision not to grant their child a place in a particular school.

However, the relatively small number of such appeals to date would seem to indicate that parents are either successfully sending their children to the schools of their choice, are happy with the enrolment policies in schools - or are unaware that they have a right to appeal.

In spite of this, some real problems with school enrolment policies do remain. Frequently, these arise out of the demand for openness and transparency.

The situation in Swords arose because there were too many pupils chasing too few places. Indeed, this represents such a serious problem for the school that it has previously tried several other approaches, including a lottery system and an interview process, the school's principal, Veronica Mc Dermott, says.

"Our basic situation is that we are the only all-girls convent school in Swords. We are over-subscribed. The school was built for 500 to 550 pupils, and we have 630 pupils at the moment. . . so the question is how best to decide how to allocate places," she says.

"This was our third enrolment policy. . . now we have the first-come, first-served basis, which we felt, after long consideration, is most in line with the Loreto ethos - to take children in not on the basis of their background or social class, for example."

McDermott says her school regrets the difficulties of parents, and had, in fact, urged them not to queue. "I went out to the parents on the Saturday morning, and I apologised," she says. "But many parents said they couldn't think of a better way. I said to them that if they could think of a better way, to let me know."

If the situation in Swords indicates the efforts of the school management to ensure they are being as fair as possible - the Loreto sisters say they are continually reviewing their enrolment policy - it is by no means typical of schools around the State, according to George O'Callaghan of the Joint Managerial Body.

Most schools are not oversubscribed, says O'Callaghan, who represents the majority of school managers here. However, he agrees that arriving at a completely fair way of enrolling pupils in those schools that are oversubscribed is impossible.

"There is no simple answer, that's the problem," he says. "Schools try to craft the best solution, but each time there are a limited number of places for too many pupils."

It is hard to escape the suspicion that at least part of the problem may lie in the perception among parents that some schools are better than others.

Despite O'Callaghan's understandable belief, given his position, that one school is as good as another, it is true that some schools have better reputations than others.

While there may be enough places in local schools to facilitate the school-going population (as was the case in Swords), the fact remains that many parents want to ensure their child goes to the "best" one available. This has the knock-on effect that such schools have too many students hoping to enrol there.

The most obvious example of this phenomenon is in the case of private fee-paying schools. Many of these are regularly over-subscribed and have lengthy waiting lists.

The Jesuit order is responsible for some of the State's most well-known and prestigious private schools, including Clongowes Wood College, Belvedere and Gonzaga.

One way in which some Jesuit schools decide who will attend their schools is through an interview process, according to Jim O'Connor of the Jesuit Education Centre.

While each Jesuit school would draft its own admissions policy, he says the interview process aims to identify parents who would support the "fundamental characteristic spirit" of their schools.

But is this not another way of saying the Jesuits cherry-pick the students they want to attend their schools?

"You could look at it both ways," he replies. "Why do parents want their children to come to our schools in such large numbers? They are also choosing our schools.

"If the school has a very definite sense of purpose of what it's about, which we do, some people can identify with that. I think our processes are very clear and open. People can pay fees provided they will be able to support the fundamental characteristic spirit of the school. And I'd make no apology for that. If we are saying we are a Jesuit school, we have to ask are there any criteria we want in families that are going to be associated with the school?"

"What we would say is that we are learning as we go along. We are reviewing out enrolment procedures all the time. At the minute, that's the system we have."

The question of school enrolment policies is clearly a difficult one to address. While some progress in the areas of openness and accountability has been made in recent years, this has also given rise to a number of other problems for both schools and parents. For now, we will continue to see parents queuing outside a school to secure a place for their child.