Published by The Guardian, Wednesday 3 August

Today’s Naplan results show that literacy and numeracy skills among Australian school children have plateaued. Average scores are flat for most states, and the number of students below the (already low) national minimum standards have barely changed.

It’s a concerning outcome and federal politicians have immediately entered the fray. The Coalition is arguing that the results show that money alone is not the answer, and that a fresh approach is needed. Labor proposes fully funding the Gonski reforms.

Above all, the results demand explanation. Why are outcomes in literacy and numeracy failing to improve despite increased focus on these core skills? Why hasn’t increased funding made a difference? Who is to blame, and what should we do now? Today’s results cannot provide the answers, but they can help us sharpen the questions.

First we must be clear about what these results do and do not say. It is clear that no state or territory has found the key to unlock sustained gains.

Queensland has made good gains since the first year of Naplan in 2008, in part by adding an extra prep year and a strong focus on improving teaching. Western Australia has made some gains, especially in Years 7 and 9.

For the last four years, other states have flatlined or made negligible improvement in most domains. The data for writing are harder to read, but suggest that standards have slipped since 2011.

But the devil is in the details. We do not know from these results whether some schools, regions or sectors have found their own key to systematic improvement. Each state has a mix of government, Catholic and independent schools, and each sector is managed differently. Regional differences exist within each sector and schools often have high levels of autonomy.

Grattan Institute’s recent report, Widening Gaps: what Naplan tells us about student progress, also reveals big differences in student learning growth among students from different backgrounds. Students whose parents have limited education typically do worse in Year 3 and fall further behind as they move through school. Year 9 students in disadvantaged schools fall up to two years behind their peers in advantaged schools even if they did equally well in Year 3.

These β€œprogress gaps” are deeply important, and should be examined when the full 2016 Naplan results are released in December.

Second, we should be wary of simplistic arguments about funding.

Education minister Simon Birmingham is right when he says there is no direct link between increased funding to schools and better learning outcomes. More money will not lift outcomes unless it improves teaching practices in the nation’s classrooms. Yet it can take three to five years for change in practice to clearly show up in a change in learning, and up to seven years to turn a school around.

More analysis is needed to understand the link between funding and school outcomes in Australia. The most β€œscientific” approach is to take similar schools and randomly assign different levels of funding – but this has major ethical problems.

In the absence of such a randomised controlled trial, there are two good ways to understand the impact of funding on performance. One is to look at schools that have had a solid boost in funding over time and see whether that has lifted their results. A second is to compare schools from similar backgrounds but with different levels of funding and to see whether those that are better funded are doing better in comparison. Few Australian studies have used these approaches.

We must also look at where the extra funding has gone. Although both sides of politics back needs-based funding in principle, the dollars have not flowed to where they would make the most difference.

Despite the fact that government school systems have much higher proportions of disadvantaged students, Catholic and independent schools received bigger increases in government funding between 2009 and 2014, both in percentage terms and in absolute dollars per student. Once private funding is taken into account, government schools received half the increase in net recurrent income per student compared to Catholic and independent schools.

Third, we must acknowledge the other factors that may influence outcomes. In particular, Australian policy has for many years emphasised the value of increasing school autonomy along with increased accountability, and the importance of parental choice. It is time to re-evaluate these system-level policy approaches: are they making things worse by encouraging schools to choose their own adventure?

By contrast, successful education systems around the world focus much more on rigorous, consistent teacher practices in the classroom, on developing cohorts of expert teachers whose job is to support other teachers, and on use of data within the classroom – rather than national benchmarking such as Naplan – to improve teaching and learning.

They also increase the attractiveness of teaching as a profession, and restrict entry into teaching degrees, approaches that Australia has talked about but not yet nailed.

These ideas are not new in Australia. But they are not yet central to our policy and our practice. Real change will come not from arguments over funding but from the hard yards of improving teaching practice.