Myth-busting rightwing prejudices - class sizes | The Jackal

10 Jun 2012

Myth-busting rightwing prejudices - class sizes

Last night, One news interviewed so-called education expert and governmental advisor John Hattie who claimed that changing the student teacher ratio didn't make much of a difference to student achievement. He was also on Q+A today, and was very unconvincing, displaying all the trademarks of presenting disinformation.

The first thing that struck me was how goddamn awful his presentation to treasury (PDF) looks. But more specifically the garishly presented and badly laid out data is all over the place and without proper reference to where it was sourced.

John Hattie
It claims that "Hundreds of evaluations of reducing class size has zero effect on achievement," but then claims that learning achievement is increased by 0.2 over time for intermediate and 0.4 for preschool.

Keep in mind that these numbers are not percentages; they're an effect size. Hattie also claims that finances available to a school have an effect size on student achievement of only 0.12. This would show that class size is in fact more important than funding.

But there's a huge contradiction here, with the garish report to treasury saying class size has an effect of 0, 0.2, 0.4, and this report by John Hattie from 2003 (PDF) that says the overall effect size is negative 0.05. This simply does not compute.

Hattie is claiming in the latter report that more students per teacher increase achievement outcomes. Around 96% of parents and teachers disagree with the confused professor, mainly because the more one on one teaching time a student gets, the better educational outcome is achieved.

The report also puts the effect size of instructional quality at 1.00. While there is no doubt that teacher quality has a large effect on educational outcomes, blaming teacher's fits nicely into the right-wings agenda, whereby they can cut funding and increase the amount of students in classrooms while criticizing teachers for the resulting low achievement outcomes. Approximately 7 to 20% of school leavers are technically illiterate in New Zealand.

To his credit, Professor Hattie states:

We need to direct attention at higher quality teaching, and higher expectations that students can meet appropriate challenges - and these occur once the classroom door is closed and not by reorganizing which or how many students are behind those doors, by promoting different topics for these teachers to teach, or by bringing in more sticks to ensure they are following policy.

But this does not excuse National's complete rubbish argument that teacher quality would be improved by increasing class sizes. Hattie has also contradicted himself by writing in 2003 that student/teacher ratios should not be changed, but then advises National that they should be. Perhaps he likes changing his message dependent on who is in power?

The main problem is that Hattie fails to find a long run impact on attainment, he measures the effect on small numbers of students where the variable is reduced, his conclusion does not use stringent conditions to decide what studies to disregard and many if not all of the studies he has used have methodological problems. This almost guarantees that Hattie's findings for the relationship between student/teacher ratio and student learning is biased.

So let's look at a few major international studies that are not biased:

The Impact of Class Size and Number of Students on Outcomes in Higher Education (PDF):

Reducing class sizes and the total number of students that a faculty member is responsible for teaching in a semester will lead to significant improvements in student outcomes.

Class size reduction in grade K-3 (PDF):

Reducing class size in Grades K-3 has been found to have academic benefits in all subject areas, especially for children living in poverty. Studies published since the mid-1980s show that classroom behavior and test scores improve while students are in small classes. Further, the improvement persists through the middle school and high school years, even though students return to full-size classes. To reap the full range of benefits, it is important that pupils enter small classes in the early years (Grades K or 1) and continue in small classes for three or more years. Students who attend small classes are also more likely to take college-entrance examinations; this is especially true for minority students.

The effect of class size on the teaching of pupils aged 7-11 years (PDF):

Practical tasks become less common, teacher demonstrations increase and pupils have less ‘hands on’ experience. So, though the curriculum coverage remains the same, the tasks through which it is experienced are different, and in some ways more superficial. However, this possible linkage between types of task and class size is mainly based on suggestions from the case studies and needs more thorough testing. 
Our results suggest several other ways in which smaller classes allow opportunities for teaching, though these flow less obviously from less children in the class. The first is maximizing individualization and differentiation by teaching to small groups. This would have the benefits of interactive whole class teaching, but would be potentially more focused and better differentiated in terms of pupil ability. It is perhaps here that one might seek to maximize the effectiveness of individual attention. Other areas have been couched in terms consistent with Anderson’s (2000) model and include: personalized, appropriate instruction; more adventurous teaching that extends the teaching repertoire, a more active (less passive) role for pupils, that includes more opportunities for help seeking.

Conclusion: Whole class teaching is not an acceptable alternative to individual support of pupils’ learning, increasing the amount of students per teacher has a detrimental effect on learning and John Hattie should not be advising the government with biased research.

It's understandable that the garish report was laid out in a way that treasury officials and National politician's could understand, but the blatant contradiction between the two reports and Hattie claiming increasing class sizes improves student achievement gets a big fat F for fail!