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Class Size – The Realities

July 23, 2020 in Teacher Life - No Comments

Class Size – The Realities

July 23, 2020 in Teacher Life - No Comments

With parts of the world pulling themselves out of their pandemic restrictions, schools are resuming face-to-face instruction. Even some countries that are still in the grips of COVID are opting to bring school back. As we return to the classroom, we may be wondering about the effectiveness of teaching with the number of students physically in the room.

Class sizes. What a polarising topic. One the one side we have classroom teachers who know less students in the room means a better experience for everyone involved. On the other side we have policy makers focusing on the cost-benefit of having less students in each individual classroom.

I’m sure that, like me, you have had experience with classes of all different sizes, particularly if you teach secondary. And I’m also sure that, like me, you know class size isn’t the only factor that influences student outcomes. But it is one that is talked about often in the staffroom, and from there all the way up to educational policy.

Hattie, a name widely known in educational circles, suggested that class size doesn’t make a difference to the quality of education. Yet the research suggests otherwise, and the practitioners (you) can see the differences first-hand. It is an area of research that seems to be trickling along – every now and then someone comes out with a new study related to one aspect of class size. This has made researching for this article a little tricky, but below I have compiled what I found, and some of it might be very surprising for some of you!

Across the Globe

The Organisation for Economic Co-operation and Development (OECD) website provides a great insight into class sizes across the globe. If you are interested in looking at the data for yourself, head here. The data sets below are for 2017, which is the most recent data available. You can play around with looking at previous years – some countries have increased class sizes and some have decreased. You can also compare public and private schools if you’re interested.

I’m sure some of you will find your country below and be shocked – the numbers portrayed here are averages, and of course your experience might be completely different. When I was working in London, for example, a colleague had a year 7 or 8 science class with 36 students in it – so many that there weren’t physically enough desks in the room for them all. And here in Aus I don’t think I’ve ever taught a lower secondary class with 22 students or less.

Note there isn’t data available for senior secondary/high school – I can only assume this is because the numbers vary so significantly due to the types of classes being taught.


Average class size globally 2017

Many Western countries point to Eastern settings as a reason why class size ‘shouldn’t’ matter. It is well known that countries like Singapore and China have large classes, and also that their educational outcomes seem quite spectacular. Those who choose to use this as their backing conveniently ignore the cultural differences at play that the rest of us can see so clearly. It is suggested that the reason why such countries can have large classes and still operate so effectively is because of the Confucian heritage and social norms, which are significantly different to what we experience and expect in other countries.

For some, these averages are far below what they are personally experiencing. So much so that in recent teacher strikes in the US many teachers were specifically picketing for smaller class sizes. While the US average sits around 26 students in a junior secondary class, the reality for some teachers is pushing very much closer to 50 students in a single class.

Benefits to Reduced Class Size

Thought about logically, there can be many many benefits to having less students in a classroom. Of course policy makers want to focus purely on academic outcomes, which seems to be the only factor that really influences educational budgets. But, as we know, there are so many factors that influence academic achievement, and academic achievement isn’t the only thing teachers and schools are held responsible for.

There are few methodologically sound papers that look purely at class size and academic outcome – one of the best known of which is Project STAR from the late ’80s. The results from this were clear – students in smaller classes (13-17 students) achieved 8 percent higher in reading and 9 percent higher in math testing than those in classes with more than 17 students. They were even found to be more likely to take college-entry exams, and the effects were stronger for minority and less-affluent students.

From personal experience, having less students in your class means you are better able to:

  • Deal with major behavioural incidences
  • Spend more time with each student individually
  • Provide more one-on-one or small-group help
  • Better monitor student behaviour, progress, understanding, and outcomes
  • Build better relationships with the students
  • Provide different teaching and learning experiences that may be difficult or impossible with larger student numbers
  • Maintain contact with parents/guardians, as well as other school officials such as guidance officers or special education support
  • Differentiate learning materials
  • Tailor your lessons to student’s interests
  • Spend less time overall on marking, or more time on each individual piece

All of these things surely contribute to better student academic outcomes, but they also contribute to better mental health for the teacher themselves. The decrease in stress experienced by being responsible for less individual students is something that cannot be overlooked, and I’d love to see someone study this aspect. Surely it’s less stressful for the students too, and since we are ever-increasingly responsible for our students’ mental and emotional well-being (on top of their academic outcomes), this must come into account too.

It seems my own personal experience matches up with the research (and I’m sure yours would as well). Dr Zyngier found in his study:

  • Teachers were more able not only to complete their lessons in smaller classes, but to develop their lessons in more depth;
  • Teachers moved through curricula more quickly and were able to provide additional enrichment activities;
  • Teachers reported that they managed their classes better, and classes functioned more smoothly as less time was spent on discipline and more on learning;
  • Students received more individualised attention, including more encouragement, counselling, and monitoring;
  • Students were more attentive to their classwork;
  • Students had to wait less time to receive help or have their papers checked, and they had more opportunities to participate in group lessons.

Another study suggested some key benefits of a better teacher-student ratio included teachers being able to provide more individual feedback and support, and monitor student progress. Conversely, larger class sizes meant that the teachers were less effective in implementing their teaching and learning activities, as well as communicating with and involving every student.

Through many of the studies and articles I looked at, they all seem to suggest the same thing: the benefits are not universal. Gifted and talented students don’t seem to benefit as much as students who comes from low socio-economic backgrounds, have English as a second or additional language, or have lower academic outcomes to begin with. Interestingly, the benefits are highest when smaller class sizes are used in the first four years of schooling – these benefits appear to follow students through the rest of their schooling.

Difficulties with Reducing Class Size

The first one that comes to mind is, of course, the money. Smaller classes means more teachers and more physical classroom space – these things obviously cost money. Money that might not be available.

Finding more teachers is not always possible either – many countries around the world are crying out for more teachers because they are apparently in a teacher-shortage crisis. This leads to countries like the UK and US hiring non-trained teachers to fill the gaps, and then this conversations turns into one of quality over quantity. Is it better to just have *more* teachers, should we be up-skilling the current teachers, or should we be waiting to decrease class sizes until we have more trained teachers available? One study in the US found that having ‘lower-quality’ (read: less well-trained) teachers to fill the gaps reduced the benefits of having a smaller class size, particularly in schools in economically disadvantaged areas.

In terms of physical space, this is another contentious area. Our global population is increasing, but our land size is not. This means schools are having to get creative with additional classroom space, especially when they do not receive the funding to provide for it. The vast majority of schools simply don’t have the money or land space to just build more buildings, or add levels to their existing ones. Temporary classrooms and converting non-classroom spaces are quick fixes, but of course pose their own problems.

Some policy makers have gone so far as to frame the issues as a this-or-that – sure, we *could* reduce class sizes, but that would mean no wage increases. Obviously all money has to come from somewhere, and if there is extra money to spend then the needs of the school/area must be properly analysed. But class size should be included in those analyses, and class sizes be reduced where possible and practical.

In a meta-analysis of the current research, it was found that only three papers out of 112 believed the costs outweighed the benefits. Dr Zyngier suggests that if the cost-benefit discussion is getting nowhere, to implement smaller class sizes in only the early years of primary school, where the greatest benefits appear to be seen.

Reduction Alone is Insufficient

Studies conducted in Australia suggest that reducing class size alone is not effective in improving academic outcomes, and that the impact differs depending on the demographic of students in the class.

The research suggests that teachers need additional training in pedagogy that better aligns with smaller class sizes in order for it to be more effective. Teaching with the same pedagogical approaches as a larger class seem to be less effective, whereas teachers who adjust their style to focus more on individual students or increase the quality of their instruction showed greater promise. The problem here is one of further professional development – teachers need support to change pedagogical approaches, and this can’t happen until further research reveals the best and worst pedagogical approaches based on class size.

So, What is the ‘Ideal’ Class Size?

Unfortunately, this is still up in the air. It largely depends on the local dynamics at play – socio-economic status of the area, teacher ‘quality’, individual student attributes, individual teacher attributes, physical facilities, school culture… the list goes on. As with any social issue, you cannot look at one aspect on it’s own as a be-all-end-all.

DM Whitmore has found that the ‘ideal’ is somewhere between 15 and 40 – quite a significant range. To combat the confusion though, it is clear from the research that any reduction in class size within this range leads to beneficial outcomes for student learning.


What are class sizes like for you? Do you align with the averages? Has there been any significant changes post-lockdown?

Photo by NeONBRAND on Unsplash


Emily is a secondary science and math teacher in Australia. She enjoys sharing the real and human teacher life, facilitating the ‘light bulb’ moment in her students, and drinking tea and wine.

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