An investigation has uncovered serious problems with the marking of last year's Junior Cert subject, Civic, Social and Political Education (CSPE), which was taken by over 58,000 students.
The investigation was prompted after the marks of over 600 students were upgraded last month.
The Department of Education asked the National Council for Curriculum and Assessment (NCCA) to find out why the marking appeared to be unusually harsh in many cases.
The investigation has found many CSPE examiners marked project work harshly, with many students awarded very low or even zero marks.
The project work in CSPE makes up 60 per cent of the overall marks and normally involves students doing a survey or interview in areas such as drugs, alcohol or smoking.
The investigation has found that examiners marked candidates down because they dealt with these issues without referring back to the seven core concepts on which CSPE is based. These mostly revolve around civic rights and responsibilities.
The NCCA recommends that, in future, students' work should not be judged solely on its relevance to the seven CSPE concepts, but also on its own merits. It says this should prevent students in future years getting zero marks in this section.
The Department of Education's marking scheme is judged to be too rigid by the NCCA investigation. The original reason students were asked to refer back to the core principles of CSPE was because the Department was worried students might get their projects off the Internet.
The upgrades ordered last month were the second embarrassment suffered by the Department of Education in relation to last year's exams.
Before Christmas it awarded revised grades to more than 200 Leaving Cert business studies students.
The problems with the CSPE first came to light during the regular appeal process after the results were issued last year. More than one-third of the 336 students who appealed were given an upgrade.