High-performing schools found in all deciles

For too long, many New Zealanders have viewed low-decile schools as lower quality.

It is easy to see why. Looking at most NCEA league tables, any parent will quickly see high-decile schools at the top and low-decile schools at the bottom.

Reading Education Review Office (Ero) reviews of your local schools will tell you a similar story. Low-decile schools are disproportionately categorised in the poor-performing category compared to middle- and high-decile schools.

At the same time, many parents have heard from others that the high-decile school across town is doing spectacularly in NCEA, music and sports.

Given all the information available, it is not surprising many parents have flocked to high-decile schools in an attempt to get the best education outcomes for their kids.

While existing measures of school performance have their merit, all produce measures of performance that are a mix of family background and school contribution. Producing better education outcomes for students is much easier for schools dealing with kids from highly educated parents in advantaged communities.

Last month, the New Zealand Initiative released the results of more than a year’s worth of work in Statistics New Zealand’s data lab developing a better measure of school performance.

Our results show that, after accounting for the contribution of family background, most schools — about 80 per cent — perform similarly.

However, we also found 42 decile 1 and 2 schools that outperformed 75 per cent of every secondary school in the country. In contrast, we also found nine decile 9 and 10 schools in the bottom 25 per cent of every secondary school in the country.

Using data from Statistics NZ’s Integrated Data Infrastructure (IDI) — the country’s largest research database — the initiative developed a revolutionary school performance tool that provides the Ministry of Education and Ero a better measure of school performance.

Otherwise known as a contextualised value-added model, our tool is unique in NZ in that it separates the contribution of each school from the contribution of each student’s family background.

This gives the ministry and Ero better and more relevant information on secondary school performance.

The initiative analysed data on nearly 400,000 students from 480 secondary schools over 10 years to determine how secondary schools are performing after adjusting for differences in family background.

The results are in stark contrast to what many believe about the quality of our lowand high-decile schools. We find highperforming schools across all deciles.

The purpose of our work was not to create new league tables; it was to get a better measure of how our schools are performing so we can lift the absolute level of education in NZ.

Using this method, the ministry and Ero could identify the top-performing schools and learn what types of practice are the most effective in improving the outcomes of our students. In doing so, the best practices can be disseminated across schools nationwide.

Annual reports could be sent to every principal at every secondary school, providing them objective, fair and datadriven evidence on their school’s performance. For some, this might reveal spectacular performance that might have otherwise remained hidden under current measures; for others, it may reveal underperformance that may have been concealed because of the advantaged communities those schools serve.

This kind of analysis could be used by the ministry to evaluate any education policy affecting secondary schools. At the same time, it could be employed by Ero to evaluate school interventions.

The work presented in our report, In fairness to Our Schools: Better measures for better outcomes, demonstrates what can already be done with the data available to the ministry. It is time for the ministry and Ero to step up. It is time for better measures, better information, and better outcomes.