Some information from Charles Achilles who has researched class size and student / teacher outcomes since 1983.
Studies since 1980 have advanced the knowledge of the importance of small classes, especially in the early years of schooling.
The early years provide a time of "task induction" and socialization to the routines and expectations of a brand new environment and experience: Who are these people? What are they doing to me? What do they wand me to do? Wow! What is this place? Given the needs to learn this new job and how to be part of a large group(not family, not playmates), perhaps it is enough if in the first few grades (K-2 or so) the child learns the language of words (literacy), the language of numbers (numeracy), the expectations and geography of the school, and how to get along (in groups, with authority, with students who are different, etc). These major tasks are not well learned if the youngster is but one of a herd.
Not all students come to school from the same experiences, backgrounds, languages, physical and mental abilities, etc.... As students age and experience school they become more "standard" and more unique. Especially in the early stages, this daunting work requires appropriate-sized groups (classes).
Our studies show that small classes are not just adding teachers and doing "business as usual." Small classes are more preventative than remedial (Once you get into bad habits, its hard to change. Consider smoking). The results of early small-class experiences appropriately used are both short-term and long-lasting. To get these benefits, at least three conditions must be met:
Additional strategies that support enduring improvement in student outcomes include:
The charge often heard is that teachers in small classes don't do anything much "different" than do teachers in larger classes, so "If you do what you've always done, you'll get what you always got." This falls by its own weight, if only that teachers in small classes have different teaching environments (fewer students - more space/person, less noise, more materials, different arrangements of spaces for learning). Space influences behaviour and learning.... Many reasons / theories support why small classes work better than larger classes and some are independent of what a teacher does. As teachers are provided opportunities to teach - not just manage - they will use better what they were taught to do, and will learn and share improved practices and methods.
None of us would disagree with any of the above. However, all of Charles Achilles' statements above are based on solid research. Long lasting improvements in students' outcomes have been achieved in a wide variety of schools across America, regardless of the initial quality of the teachers, facilities, environment, resources, socio-economic background of the district, etc.
Many schools have had to completely reorganise their schools and put a larger percentage of their funding into teaching staff (often at the expense of non-teaching staff).
The difference between Student Teacher Ratio and actual class size provides some guidelines for planning. According to Charles, if a site has a Student Teacher Ratio of 12:1 (including all non class teachers, principal and deputy), that suggests enough personnel to work towards class sizes of 15:1 or so (in the first 4 years of schooling) and still keep some teachers for special assignments. The larger the school the easier this is.
Australian Education Union 9/7/2002 Seminar Notes by Di Russell