An optimum class size?
Is there a ‘best’ class size? Do benefits from small classes only appear if reduced
below 20, as US research suggests? One advantage of our research, in contrast to class
size reduction experiments, like the STAR project, is that we did not restrict class sizes,
and we can therefore make judgements about the effects of the full range of class sizes
found in our schools. Our results suggest a complex picture when it comes to judgements
about optimum class sizes. In maths, during the first year, there are benefits resulting
from decreases in class size across the full range of class sizes, not just below 20 in a
class. However, in the case of literacy, the size of class below which benefits are most
marked varies according to the child’s level of attainment prior to school entry, as we
have just seen. Effects for the lowest attainers are most marked when they are 25 and
smaller. In general it is probably over simplistic to talk about optimal class size in an
exact way. Teachers’ judgements about preferred class sizes are likely to be affected by
what they have experienced and what they perceive as realistically achievable.
Judgements are also likely to be affected by culturally bound views about teaching and
about learning, and for these reasons it would not be surprising if views differed between
countries. We need, therefore, to be careful about comparisons across countries and
attempts to pin down an optimal class size.
Class size and extra staff and adults
There was no clear evidence for any year, for either literacy or maths, that additional
staff or additional adults in the class had an effect on children’s progress, and there
was no apparent ‘compensation’ effect of having extra adults in the class. This result is
consistent with the STAR project, where it was found that there was no compensatory
effect of having extra staff in larger (regular) classes. It is also supported by other recent
research (Finn, Gerber, Farber and Achilles, 2000). The consistency of results from these
studies makes provocative reading. However, as reported in a separate paper (Blatchford,
Martin, Moriarty, Bassett and Goldstein, 2002) we were able to go beyond statistical
relationships between the presence of extra staff and students’ achievement and look
more closely and in a more rounded way at the contribution of teaching assistants, on the
basis of teacher questionnaires and case studies. We found that teachers were largely
positive about the contribution of teaching assistants but the case studies revealed
considerable variation in their effectiveness, and it was this that was likely to account for
the lack of clear associations with children’s attainments.
Dealing with class size differences: implications for teaching
We have seen that a small class has the potential to allow teachers to provide more
individualisation of instruction, so an important next step in this analysis concerns how
the teacher DEALS with this classroom contextual feature, that is, with class size. She
can deal with it inappropriately. Evertson and Randolph (1989) have offered a
fascinating account of observations in STAR small classes. They argue that the
adherence of teachers to established methods of reading and maths instruction (as well as
the mandated curriculum in Tennessee, which emphasises basic skills) may have
minimised differences between processes in small and regular classes. In a similar way,
our case studies indicated one feature of smaller classes - a tendency to allow
immediate feedback - could lead to frequent interruptions, and needs to be watched
carefully by teachers. On the other hand a teacher can deal with small classes
effectively. We have documented examples of teachers in small classes doing a
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