Does class size matter?

Many moons ago – summer of 2009 – there was an AP piece about the increase in class sizes across the US and further chatter on blogs like Eduwonk and the like that it isn’t really about class size but more about teacher effectiveness – which is right on. An effective teacher is far more important than smaller classes – at least the little-here-little-there small that school districts tend to implement. As researcher Eric Hanushek said in the AP story, “All the research suggests the number of kids is much less important than who is teaching the class.”

Friends have asked about this issue, and below is something that a former colleague of mine pulled together on it for our PTA. (See it also here.) Yes, it’s a little wonky but gives a sense what the research says about class size and its impact on achievement, student behavior, and teacher satisfaction.

Here goes:

Class Size and Impact on Student Achievement/Performance: The one seminal study – known as the largest, best-designed experiment on the impact of class size – is the STAR Project (Mosteller, 1995), completed in 1995. This longitudinal study controlled for unwanted variables for which previous studies on class size had been criticized, such as teacher training, socioeconomic background, and curriculum material and programs. The results showed that (1) long-term exposure to small classes (in grades K-3) generated substantially higher levels of achievement and the (2) extra gains associated with long-term exposure to small classes were greater the longer students were exposed to those classes. In addition, although all types of students experienced extra gains from long-term exposure to small classes in the early grades, those gains were greater for students who are traditionally disadvantaged in education.

The study also showed that students who were exposed to small classes in the early years were able to sustain the advantages in achievement as they moved on to upper grades. The students were months ahead of those from standard classes on the local standardized test, earned better grades, and dropped out at a lower rate. In high school these students took more advanced and foreign language courses, graduated at a higher rate, and volunteered to take college entrance exams at a higher rate than students not exposed to small class sizes in the early years. Additional conclusions drawn from STAR include:

• The extra gains found for long-term attendance in small classes (in the early grades) continued to appear when students were returned to standard classes in the upper grades
• Extra gains associated with long-term attendance in small classes (in the early grades) appeared not only for tests of measured achievement but also for other measures of success in education
• The greater gains experienced by students from groups that are traditionally disadvantaged for education were retained when those students were returned to standard classes (Biddle & Berliner, 2002)

Other studies conducted in Wisconsin (SAGE Program) and California (Class Size Reduction Program) have offered valuable lessons in regards to the effect of class size. First, implementation of small classes has to be planned thoughtfully and funded adequately. Also, extra gains in achievement from small classes are larger when class size is reduced to less than 20 students (Biddle & Berliner, 2002).

Class Size and Impact on Student Behavior: Finn, Pannozzo, & Achilles (2003) reviewed 11 studies on the relationship between class size and student behavior. Their review found:

• Students in small classes contributed more to class activities and paid more attention in class
• Student engagement in academic tasks was higher in small classes than larger classes
• Overall, most of  the studies showed a positive impact of smaller classes on students’ social behavior by decreasing antisocial behavior and promoting prosocial behavior
• Students in small classes are less likely to be disruptive
• Smaller classes appear to promote an atmosphere in which students are more supportive and care about each other

A study by Koth, Bradshaw & Leaf (2008) showed that 5th grade students in smaller classes tended to view the school climate as safer, especially in regards to order and discipline. The authors stated that class size alone may not be a great influencer of school climate and student behavior perception.

Class Size and Impact on Teacher Satisfaction: Research on class size and impact on teacher satisfaction is scant; however Finn et al. (2003) reviewed nine studies and found the following:

• Teachers in small classes interacted more with students
• Teachers in small classes tolerated more noise in class
• Teachers in large classes spent more time on “nonacademic management” of class
• Teachers noted improved interpersonal relations and interactions with students in small classes
• Teachers in small classes had more knowledge of children, their families, and their home background
• Teachers in small classes allowed students more freedom

A UK study (Blatchford, et al., 2006) investigated effects of class size on students 7-11 years old. They used qualitative information from teachers’ end-of-year accounts and data from case studies with quantitative information from systematic observations. Results showed that there was more individual attention in smaller classes, a more active role for pupils, and beneficial effects on the quality of teaching. It is suggested that teachers in both large and small classes need to develop strategies for more individual attention but also recognize the benefits of other forms of learning – for example, group work.