School authorities often complain that classes are too big. They argue that teachers cannot be expected to give their students the individual attention they need if there are too many students in the class. On the surface, this excuse seems to have some merit. Common sense tells us that in smaller classes, teachers can devote more time and attention to each student.

However, many studies show that small class sizes do not guarantee that children will receive a better education. The student-teacher ratio in public schools in the mid-1960s was about 24 to 1. This ratio dropped to about 17 to 1 in the early 1990s, meaning that the average size of schools classes dropped by 28 percent. However, over the same time period, SAT (School Aptitude Test) scores fell from 954 to 896, a decrease of 58 points or 6 percent. In other words, student academic performance (as measured by SAT scores) declined at the same time that class sizes declined.

Eric Hanushek, an economist at the University of Rochester, examined 277 published studies on the effects of teacher-student ratios and class size averages on student achievement. He found that only 15 percent of these studies showed a positive performance improvement with smaller classes, 72 percent found no statistically significant effect, and 13 percent found a negative effect on performance.

It seems to go against common sense that the academic performance of students could decrease with smaller classes. One of the reasons this happens in public schools is that when class sizes decrease, schools have to create more classes to cover all the students in the school. Schools then have to hire more teachers for the greater number of classes. Yet public schools across the country are already having trouble finding qualified teachers to fill their classrooms. As a result, when small class sizes increase the need for more teachers, schools often have to hire less qualified teachers.

The quality of teachers and teaching methods are much more important

Unsurprisingly, teacher quality is much more important than class size in determining how children do in school. William Sanders of the University of Tennessee studied this topic. He found that teacher quality is nearly twenty times more important than class size in determining student academic performance in class. As a result, reducing class sizes can have the opposite effect of hurting a student’s education, rather than helping it.

Similarly, a study on class size by policy analyst Jennifer Buckingham of the Sydney-based Center for Independent Study found no reliable evidence that students in smaller classes perform better academically or that teachers spend much more time with them in these classes. Buckingham concluded that a 20 per cent class size reduction cost the Australian government an extra $1,150 per student, but she added only two extra minutes of instruction per day for each child.

Reducing class sizes cannot solve the underlying problems in public schools. No matter how small classes get, nothing will help if teachers are poorly trained or their teaching methods are unhelpful or destructive. For example, if teachers use full-language or “balanced” reading instruction, they can cripple students’ reading ability no matter how small the classes. Even if classrooms had one teacher for each student, that child’s reading ability could still be affected if the teacher used these methods of reading instruction. In fact, smaller classes might give the teacher more time to (unintentionally) hurt each student’s reading ability.

Here’s an analogy on this topic of class size vs. Teaching Methods: Suppose a riding instructor were teaching a girl to ride. This instructor’s teaching method was to tell the puzzled girl to sit back on the horse, facing the horse’s rump, and for her to control the horse by holding onto its tail. Does it matter that the student to teacher ratio in this riding class is one to one if the instructor is a jerk or uses bad teaching methods?