Small schools do better than large schools on a variety of school variables including student achievement according to a new review of studies on the effects of school size on education. Further, it found that students from disadvantaged social and economic backgrounds are the major beneficiaries of smaller schools.
The review examined 57 studies conducted since 1990. The studies assessed the impact of school size on a variety of school outcomes, cost efficiency and teachers. The vast majority examined the relationship between school size and various measures of student outcomes. It found that smaller schools were better suited to most purposes.
The review was published in a recent issue of the Review of Educational Research, the journal of the American Educational Research Association. It confirms the conclusion of many earlier studies.
Effects on student outcomes
Various studies have considered the impact of school size on outcomes such as student achievement, the achievement of disadvantaged students, attendance and retention rates at school, student engagement at school, curriculum options, extra-curricular participation, self-esteem and social behaviour.
Of the studies reviewed, 10 provided evidence about the relationship between school size and the academic achievement of elementary (primary) school students. A majority of them found that achievement increases as school size decreases. None found evidence that achievement rises with increases in school size. These findings are consistent with those of earlier studies.
Many more studies have been carried out on secondary schools and the evidence here is mixed. Some studies show found achievement increased with size, others that achievement increased up to a certain size and then begins to decline and yet others showed that student achievement declined as school size increased.
It has been suggested that studies finding a positive relationship between high school size and student achievement may not have adequately had regard to the higher drop-out rates typically associated with large secondary schools. Improved average school performance in large high schools may simply be a function of the increased drop-out rates found in such schools. Few of the studies reporting a positive relationship between school size and achievement took this into account.
Several studies have examined the effects of school size on more or less disadvantaged students. All of them have found that small schools are associated with better outcomes for disadvantaged or low socio-economic status (SES). None of the studies found negative effects for advantaged or high SES students.
Most studies since 1990 have shown that student attendance and retention rates are significantly better in smaller than larger secondary schools. Some 13 studies have considered the impact of school size on attendance and dropping out of school. Only one study reported a positive relationship between retention and/or attendance and larger schools; 5 studies found that retention and attendance was better in small schools while 3 reported evidence favouring mid-size schools and 4 reported non-significant relationships.
Six studies have examined the relationship between school size and student engagement in school other than simply attendance and retention. One of these studies included evidence from both elementary and secondary schools, the remainder were concerned only with secondary schools. All the studies indicate significantly stronger student engagement in smaller schools compared with larger schools. Several studies prior to 1990 reported similar results.
Only 3 studies examined the relationship between school size and curriculum breadth. They suggest that curriculum options are more varied in larger secondary schools. However, breadth of curriculum is no longer seen as a justification for large schools. While it is often cited as a major advantage of large comprehensive secondary schools, it seems achievable in schools as small as 500 to 600 students. Also, more weight is now being given to curriculum depth and extensive curriculum choice is now regarded as a threat to the academic progress of most students.
Four studies, all published between 1996 and 2007, examined school size effects on extra-curricular participation and all found that it decreases as secondary school size increases.
Five studies have examined the relationship between school size other student outcomes such as self-esteem, physical safety, and social behaviour. Two of the studies failed to find a significant relationship between student self-esteem and school size. Two studies, one in elementary and one in secondary schools, found reduced incidence of mis-behaviour in smaller schools.
Evidence about the costs and cost-efficiencies of schools varying in size was provided by five studies. Two of these studies report results favouring large schools, two favouring small schools and one favouring midsize schools. They offered no clear direction about the most cost efficient size of secondary schools, a result consistent with much earlier research.
These mixed results are likely due to the quite different methods used to calculate results. Most studies finding an inverse relationship between size and cost effectiveness also have a strong interest in equity as an outcome.
The review of these studies concluded that cost-efficiency is no longer a justification for large schools. It noted that most contemporary studies have concluded, unlike an earlier generation of studies, that small schools are more efficient or cost-effective. This reversal of opinion is the result of taking student graduation rates into account. Small secondary schools graduate a significantly larger proportion of their students than do large secondary schools.
The study reviewed 10 studies of the relationship between school size and several different teacher work-related attitudes. Of these studies, 7 were conducted in elementary schools, 3 in secondary schools. Of the 10, 7 reported evidence teacher attitudes were better in smaller than in larger schools. One study found a variable relationship between school size and teacher work-related attitudes and 2 found non-significant relationships. The review concluded that, while not a unanimous finding, the combined weight of these results seem to indicate that smaller school size enhances the chances that teachers will hold positive work-related attitudes.
The review concluded that it is very difficult to determine the optimal size of schools. However, it considered that there is justification for four recommendations.
First, elementary schools serving student populations exclusively or largely from diverse and/or disadvantaged backgrounds should be limited in size to not more than about 300 students.
Second, elementary schools serving economically and socially heterogeneous or relatively advantaged students should be limited in size to about 500 students.
Third, secondary schools serving student populations exclusively or largely from diverse and/or disadvantaged backgrounds should be limited in size to about 600 students or fewer. Finally, secondary schools serving economically and socially heterogeneous or relatively advantaged students should be limited in size to about 1,000 students.