Enhancing the quality of education at our schools by reducing the size of classes is a notion that is hard to resist. Surely, cutting the number of students in each class would enable teachers to pay more personal attention to each, or so most people think. No wonder about 3,500 people braced heavy rain on Sunday to join a demonstration to urge the government to reduce the size of primary classes to 25 students. But while smaller classes should reduce the workload of teachers, studies all over the world have produced no definitive evidence to show they would necessarily improve the quality of education. Rather, effective teaching and learning takes place, regardless of class size, if teachers know how to stimulate young minds and stretch their imagination. All things being equal, smaller classes are better, if only we had the money. Over the past three decades, class sizes at both primary and secondary schools have been progressively reduced. From 45 students per class, the figure for primary schools has fallen to 32 for those using the activity teaching approach and 37 for those following the conventional approach. The irony is that while a small number of popular schools are admitting more than 37 per class, the less popular cannot manage to recruit a minimum of 23 to stay afloat. It is also absurd to maintain the distinction between the two approaches, as the education reforms are all about using more lively teaching methods. The Professional Teachers' Union argues the government should use the opportunity presented by the shrinking school-age population to cut the average primary class size to 25, starting with districts hurt most seriously by falls in student numbers. The proposal sounds attractive as it could be implemented without additional funding, except that it looks more like a scheme aimed at saving teachers' jobs than enhancing quality. Secretary for Education and Manpower Arthur Li Kwok-cheung says class sizes at many schools have already dropped below 30, but quality has not necessarily gone up. In progressively cutting the class sizes at more schools, he will be guided by the results of a pilot scheme being conducted at 37 schools to test different ways of teaching such classes effectively. The union has dismissed his strategy as a delaying tactic and one aimed at exploiting the falling numbers of school children to weed out, unfairly, what are regarded as non-performing schools. Differences over the strategy and timing of implementing smaller classes have seen Professor Li clashing repeatedly with Professional Teachers' Union chief and legislator Cheung Man-kwong. What is most discouraging about their row is that it might have discouraged many talented young people from becoming teachers. The pair should both shelve their emotions and focus on bridging their differences. The sooner they bury the hatchet, the better. What the community needs from them is a joint action plan to boost teacher morale and the quality of education, not more bickering. Class sizes in Hong Kong are definitely too large. Many of the reforms aimed at encouraging teachers to adopt a student-centred approach will remain impossible ideals unless classes become smaller - at both primary and secondary level. It is inconceivable, for example, to teach liberal studies, a core subject in a reformed senior secondary curriculum emphasising creative learning, to classes of 40 students. Considering Hong Kong's situation, however, having 25 students per class would seem a luxury. A more realistic and appropriate number to aim for is 30. It is a norm that has proven successful at local international schools and those run by the English Schools Foundation. Money will need to be found to fund the reduction of class sizes, but it will be well spent. We risk failing to produce an educated workforce that can meet the needs of an information economy, if classes remain big and one-way monologues from teachers remain the most 'effective' method of teaching.