Reducing class sizes and raising standards are the Government’s immediate priorities for education. But is reducing infant classes to no more than 30 actually the panacea that many people believe?

My analysis of the 1996 key stage 2 results for the 78 primary schools in my local authority shows no relationship between class size and test results. More schools with results above the average performance for the borough had classes with more than 30 pupils than schools achieving below average results. Several of the higher-performing schools had much larger classes than the lower-achieving ones.

The ability of some schools to produce very good results with large classes can be explained by introducing two further variables. When the league table of school performance is considered against the social disadvantage allowance allocated to the borough’s primary schools for 199798, there is a very high correlation between the extent of social disadvantage and test results.

Only one school in the top 25 per cent receives more than a modest social disadvantage allowance, though several receive a small sum. Only two schools in the top eight receive any social disadvantage funding. Conversely, the bottom 20 per cent includes only two schools that do not receive social disadvantage funding. All but one of the bottom eight currently receive substantial amounts.

There is also a correlation between league-table ranking and the number of pupils in the school with identified special needs. The schools in the bottom 20 per cent tend to have higher numbers of special needs pupils than the borough average, while the top 20 per cent have lower.

At least one-fifth of the pupils in most schools in the bottom group have special needs, and some schools have many more. Although the top eight schools report higher percentages for special needs than the top 25 per cent, this may reflect the attention which schools without many socially disadvantaged pupils can devote to special needs.

This analysis, based on quickly accessible published statistics, is necessarily superficial. But it would be interesting to try it in other authorities, and also to include key stage 1 results to see whether the correlations identified hold true in other areas. If they do, it raises concerns about the wisdom of making the reduction of class size to 30 a priority, without looking in depth at all factors which contribute to under-achievement.

The most practical way of reducing class size is to introduce extra teachers into oversubscribed schools. The best results in my borough were achieved by a school with classes of 34. That school would undoubtedly appreciate additional funding for more staff, as even highly achieving schools can do better. Nevertheless, enhancing the staffing levels at schools towards the bottom of the rankings would do more to raise standards, enabling a greater number of children to attain the new numeracy and literacy targets.

It would be ironic if a policy of reducing class size resulted in more staff and funding going into successful, highly achieving schools while those with classes of fewer than 30 which serve areas blighted by disadvantage received no help.

Of course, test results are only one part of the equation. Reducing class size is important in lessening teacher stress, improving classroom discipline and preventing children from having to learn in cramped conditions. Moreover, pupils of all abilities would have greater opportunities for individual attention in smaller classes.

But the Government faces both financial and practical challenges if it is both to reduce class size and raise standards. Separating the two seems essential in understanding the issues. Without specific evidence about how class size affects attainment, reducing class size in the belief that this must raise standards could actually waste valuable resources that could be usefully targeted at other problems.

It would also be useful to study in depth a selection of successful schools with large classes to discover precisely how they approach the task of education and what lessons others could learn. It would be interesting to discover whether schools that employ classroom assistants (or enjoy a committed network of voluntary helpers) produce better results than those that do not. Other relevant issues relate to teaching methods, and the experience of staff, as well as the socio-economic background of pupils and their baseline assessments.

For whatever reason, some schools with standard numbers greater than 30 children per class are functioning effectively, and might choose to continue with that intake. Rather than deeming 30 to be the holy grail, there would be more sense in identifying the best configuration for each school and allowing it to operate at that optimum. If classes were capped at 30, pupil-led funding in those schools would immediately be reduced. This could have adverse affects.

For other schools, classes of 30 may be far too large. If we are serious about tackling the cycle of under-achievement which bedevils certain areas, perhaps classes should be reduced to 20 or less to allow for more intensive input. In other schools the design of the building makes classes of even 30 particularly stressful for any teacher.

So how do we begin to tackle class size? First, someone needs to define an absolute maximum number of children that any teacher should be responsible for without assistance. Contingency plans must then be in place to deal with problems posed by and to children when the LEA cannot offer any sensible alternative placement.

One way of stimulating parental choice of some currently undersubscribed schools is to pump-prime the provision of before and after-school care. Many parents appealing against infant school placements cite the availability of child care as a reason for their appeal. Making child care widely available on all school premises could relieve congestion in some, at a modest cost - out-of-hours care could quickly become self-financing if it were charged to parents on a marginal cost basis.

Once the effect of class size on both pupils and teachers has been researched, the challenge will be to direct resources to the schools that need them most without penalising those which are functioning effectively under the status quo. We need to establish the optimum balance between levering up standards of the lowest achievers, and stretching and extending all children.

Denise Bates is a chair of governors, and chairs admission appeals panels