Statements like this, from the principal of a top-performing disadvantaged primary school, show the determination needed to help disadvantaged students to succeed.

In many ways, students from disadvantaged backgrounds start behind other children.

On average, they enter school behind their peers, learn to read later, and have more behavioural issues. Many continue to underachieve across their schooling and are less likely to go to university.

Yet it is possible for effective schools to overcome that disadvantage, as our latest research showed. And it's not just about spending more taxpayers' money on the problem.

Our study, one of the first of its kind in Australia, used NAPLAN results to identify the 18 disadvantaged primary schools across Australia that achieved literacy and numeracy results consistently above the national average across the three-year period 2015-2017. None of these schools received more funding than other similarly disadvantaged schools.

With the research including spending time at nine of the schools, interviewing principals and staff as well as observing lessons, some common factors were identified:

These six elements are consistent with the existing research on high-performing schools.

One possible reason for two-thirds of the high-achieving disadvantaged schools being in Victoria is that the state has more principal autonomy regarding selection of school staff and how budgets are spent.

Disadvantaged students often have complex needs - including any number of combined factors such as limited vocabulary, emotional wellbeing issues, and family violence.

Greater flexibility for principals allows them to respond in an appropriate way to help all individual students.

Yet this flexibility also relies on developing good leaders in schools and keeping them there. A positive school culture has to come from the top.

A striking feature of disadvantaged schools that perform well is the calibre of principals. The average tenure of the nine principals interviewed is 10 years, which is considerably longer than the national average tenure of less than five years.

More experienced school principals will likely have a greater practical understanding of how to increase school effectiveness, and positive changes generally take several years to flow through into improved results.

Good leadership, and motivated and dedicated teachers, both help cultivate a positive school environment over many years.

This is the clearest common theme across the nine high-achieving disadvantaged schools, and a significant key to their success.

While there is a range of school discipline policies across the nine schools, there are some shared practices and approaches: high expectations; a clear set of consistently applied classroom rules; and a consistently applied whole school behaviour policy.

Using data to inform teaching and track student progress was also common to all nine high-achieving disadvantaged schools.

A focus is on using data for specific purposes and not collecting data simply for the sake of it. As one teacher said to me: "We're data-informed, not data-driven."

All nine schools used data from two standardised tests: NAPLAN and the Progressive Achievement Tests (PAT) from the Australian Council for Educational Research. It is clear that ensuring these data sets continue to be available and in use is crucial to combating disadvantage.

These schools illustrate best practice. The challenge is turning this into common practice in the school system.

We need to move away from the mindset that the answer is simply to spend more money. Despite substantial recent increases in funding, there is no evidence of general improvement in results for disadvantaged students.

School systems should take an evidence-based approach and focus on what works, policy makers should focus on assisting schools maximise results with efficient use of funding.

The study findings should reassure Australians that it is possible for disadvantaged students to be high achievers.

It's hard work, but these schools show it can be done.

Blaise Joseph is a Research Fellow in education at The Centre for Independent Studies.