A severe shortage of trained primary teachers has resulted in a significant proportion of children being taught for months, and in some cases years, by untrained teachers.
School principals contacted throughout counties Sligo, Roscommon, Donegal and Leitrim said the problem was extremely serious and children's education was suffering, often during very important formative years.
The Irish National Teachers Organisation said a similar situation exists throughout the State and schools in disadvantaged areas usually suffer most.
In a two-teacher school in Arigna, Co Roscommon when a teacher left on secondment for three years, pupils had eight different teachers during one year, only one of whom was qualified.
Apart from one three-month period, the pupils were also taught by unqualified people during the following two years. As a result, some pupils were taught by unqualified teachers for two-and-a-half years.
Principals stressed they were not criticising the untrained people who do the work and said the system depended on them. But they are doing a job they are not qualified for.
One principal said it was very evident that children's education had suffered after being taught by an untrained person for their first year at school. "I think they will be affected right up through the school. There is no doubt they got a very bad start. You have to actually undo some of the work that was done - they had to re-learn some things that were taught incorrectly," she said.
Teachers point out that specific training is needed for areas such as language development, pre-reading and early reading, and early number work. Harm can be done if incorrect methods are used in the early stages.
A remedial teacher who has worked with pupils taught for long periods by untrained teachers said pre-reading and pre-number work was often ignored and children suffered later.
"People should remember that it's not a dress rehearsal - children only get one chance at their primary education," she said. A spokeswoman for the INTO said early indications from a national teacher shortage survey were highlighting the severity of the problem. In the Sligo/Mayo district there were at least 17 permanent unfilled posts and some 35 posts were filled by unqualified people. An additional eight temporary or substitute positions were also unfilled.
The INTO estimates there are more than 1,000 posts which are either not filled or are filled by unqualified people out of a total of about 20,000 posts in the State.
In the north west, schools in larger towns seem to fare better than smaller schools in rural areas.
Principals also pointed out that because of the introduction of the new primary school curriculum, more teachers were taking secondment to work on different aspects of it. Technically, once a person has Leaving Cert Honours Irish they can work as a substitute teacher, although many of those who do substitute work have degrees, but in very diverse areas, and some are qualified as second level teachers.
Mr Jim Higgins, the principal of a primary school in Riverstown, Co Sligo, said he was finding it impossible to get a qualified substitute teacher to cover for a maternity leave from January to June. "Without unqualified people we wouldn't be able to manage at all," he said.
Mr Higgins is also fighting a battle with the Department of Education for a new school. The present building dates from 1900, one room is divided by a partition and another class is taught in a prefabricated room. The sewage regularly gets blocked and the children have no proper play area.
Mr Bill Connolly, principal of the primary school in Arigna, said most of the people on the substitute panel who were qualified were retired and were only willing to do two or three days per month. Mr Terry Allen, the principal of Our Lady of Mercy school in Sligo, one of the biggest schools in the region with 32 staff, said: "The system has been relying on unqualified people for too long - it wouldn't happen in other professions, but for too long we have accepted it."