Every year the State Examinations Commission (SEC) seeks to ensure a similar proportion of students achieve the same grades across individual subjects.
Why?
It is aimed at ensuring standards are maintained each year.
In this way, similar numbers of students progress to third-level institutions annually.
It is also hoped higher education institutions and employers can be assured of the consistent quality of applicants.
Using what some refer to as a bell curve, the commission adjusts marking schemes at an early stage in the marking process to ensure a similar proportion of students secure H1s, H2s and H3, etc, year after year.
Take the Leaving Cert exam in Higher level English as an example.
The proportion of students who achieved a H1 (90 to 100 per cent) in 2019 was 2.9 per cent; the equivalent figure for 2018 was 2.9 per cent; in 2017 it was 2.9 per cent.
The pattern is repeated further down the grades.
The proportion of students who achieved a H2 (80 to 90 per cent) in 2019 was 10 per cent; in 2018 it was 10 per cent; and in 2017 it was 10.7 per cent.
Similarly, the proportion of students who achieved a H3 (70 to 80 per cent) in 2019 was 20.4 per cent; in 2018 it was 20.6 per cent.
These remarkably similar proportion of grades are achieved by adjusting the marking schemes during the marking process, depending on whether the exam has been too hard or too easy.