Far from the headline "Benefits of smaller class sizes questioned by study" (The Herald, November 24) being misleading, I think it is a more than fair representation of the situation, as the research gave no proof of benefit and, in fact, appeared to suggest the opposite.

The problem with research into class size is that it is extremely difficult to separate the class-size effect from other effects such as social background or teacher competence. The one project that seems to be accepted as avoiding these pitfalls shows benefit is restricted to the youngest and least able in the class but that this benefit does not survive as the child moves up the school. Moreover, on the subject of research, a recent report by McKinsey consultants (co-written by Michael Barber) found the quality of teachers is key to high attainment - far more important than smaller class sizes. Looking at other countries, they found there was a strong correlation between educational performance and the standard of graduate that moved into the teaching profession.

Class size is an EIS policy and it has, understandably, pursued it vigorously with threats of industrial action, lobbying of politicians and a petition that was put round school classrooms by EIS reps. Moreover, if the purpose of the exercise is cutting teacher workload, then this is completely the right way to go and fully in line with the general improvement of teachers' pay and conditions since 2000, including the justified increase in salary and a cut in class contact time amounting to 10% for primary teachers.

However, if the purpose is to increase pupil attainment, then things become less clear. The research that smaller class sizes lead to across-the-board increases in attainment is at best ambiguous while that group that has been shown to benefit from smaller classes - the least able and youngest - can be better helped through more targeted use of resources and teacher time. I refer, of course, to the highly successful literacy programme in West Dunbartonshire. Yes, it has put in extra teachers, but in a targeted way and for specific teaching/support; it has not spent money on extra classrooms to accommodate a general class-size reduction.

Also, spare a thought for what the current complexity of class size means for children starting in primary school. They may start in a small class, but this might also be a composite class as the school attempts to match classrooms, children and class-size regulations. Then, as they move up the school and on into secondary, they will find themselves being moved perhaps in and out of composite classes or into classes of 33 in the upper primary, back to 20 for English, maths and practical subjects in secondary, but 30 for other subjects, including languages. The core group may be lucky and stay together, but those on the periphery could spin around like a whirligig on a windy day. As constancy is a proven plus in educational terms, then such an experience does not augur well for those unlucky enough to be in perpetual motion.

Judith Gillespie, Development Manager, Scottish Parent Teacher Council, 53 George Street, Edinburgh.

In your article on whether smaller class sizes are beneficial or not (The Herald, November 24) you state: "Smaller class sizes could be a red herring."

You cite work undertaken by the previous administration's class-size working group which, as you pointed out, focused on a small sample of S4 pupils.

This Scottish Government is clear that the benefit of smaller class sizes comes in the early years, not at S4 level. Far from being a red herring, we are clear that reducing class sizes at those stages means more time for each child, improved behaviour and increased motivation.

That's why we are committed to reducing class sizes in P1-P3 to 18. Indeed, we stated in our manifesto that we will reduce class sizes in primary 1, 2 and 3 to 18 pupils or fewer to give children more time with their teacher at this vital stage of their development. We were also clear that headteachers should have the powers to decide on the most appropriate class sizes in later years within national guidelines. As part of the historic deal we have with local authorities, we will now work to achieve the reduction in P1-P3 classes as quickly as possible.

Fiona Hyslop MSP, Cabinet Secretary for Education and Lifelong Learning, The Scottish Parliament.