Exam Times: More than 52,000 young people will begin their Leaving Cert exams this week after spending five to six years of their lives in second-level education and two years preparing for their final State examination. It is disappointing, therefore, that some have chosen this important time to question the validity of their efforts with suggestions that the exam is being "dumbed down".

Students and their parents can feel confident that they are sitting an examination where the highest standards are being maintained and that recent suggestions of a dumbing down are unsubstantiated.

As with all aspects of Irish society, the Leaving Cert should be critically analysed and reformed when there is sound evidence for this but charges of dumbing down are unfair to our pupils, to our teachers and to the education system generally.

There are a number of reasons why students are attaining higher grades in the Leaving Cert than they were 15 years ago. Young people are working harder and smarter than we did at their age. This is a key contributing factor to the improved performance and higher grades.

The Leaving Cert is renowned as one of the most transparent examination systems in the world and students, along with their teachers, now have the right to view any of their marked examination scripts.

These marking schemes are now publicly available, resulting in increased focus on how learning objectives are tested in Leaving Cert examinations.

It is well recognised that learning becomes more effective when the learner has a better understanding of his or her learning objectives.

Furthermore, despite our large class sizes, teachers are using a greater variety of teaching approaches in the classroom. In addition, wide-ranging syllabus and curriculum reform has been undertaken by the National Council for Curriculum and Assessment (NCCA), including the introduction of the Leaving Cert applied and the Leaving Cert vocational programmes to cater for the full range of human intelligences.

One criticism of the Leaving Cert system that is sometimes reeled off is that it promotes rote learning by students looking to secure college places. If this were the case, then surely these students would not be able to repeat their performance at third level.

Data furnished by Dr Garret FitzGerald in respect of the Leaving Cert points achieved by graduating students from four Irish universities - UCD, UCC, NUIG and NUIM - in 2003 and 2004 demonstrate that the Leaving Cert examination is a reliable predictor of university performance and is therefore a valid indicator of students' intellectual capacity.

In a study carried out in conjunction with Oxford University for the NCCA, experts examined the Leaving Cert and the A-level examination (the so-called gold standard) for the purposes of awarding grades to Irish students entering British universities, including Oxford and Cambridge.

The results of this study demonstrated that the Leaving Cert compared very favourably with A levels. A further important advantage of the Leaving Cert is that most students take a broader range of subjects - usually seven - than their UK counterparts.

The fact that Irish second-level students are doing well is confirmed by a number of studies.

The OECD Programme for International Student Assessment (Pisa), for example, is the most comprehensive and rigorous international programme that assesses student performance and collects data on the characteristics of students and the institutions where they study.

In Pisa 2000, Irish 15-year-olds came fifth out of 29 OECD countries in literacy tests, with only one country - Finland - doing significantly better. The Republic also scored significantly above average in scientific literacy and close to average in mathematical literacy.

Variations in grade achievement between different subjects is worthy of careful examination and some analysis has been undertaken by the NCCA. However, drawing general conclusions from raw statistics is problematic. While it might appear at first sight that it is easier to get an A or a B in some subjects than it is in others, different participation rates and ability levels are often significant factors affecting overall attainment levels.

The fact that Leaving Cert Russian is taken by only a handful of pupils, a proportion of which are likely to be native Russian speakers, means the grades are unlikely to correspond with say Leaving Cert French, which has a high participation rate.

Likewise, it would be wrong to conclude that because a high percentage of students taking applied mathematics attain A and B grades, then it must be a soft option subject for students.

On the contrary, the high grades reflect the fact that this subject is more likely to be taken by academically minded students in the first instance.

John White is general secretary of the Association of Secondary Teachers Ireland.