The Education Ministry needs to find out why some schools are better than others at raising Māori achievement, and which initiatives are most cost effective, says Auditor-General Lyn Provost.
Ms Provost has published a report Education for Māori: Using information to improve Māori educational success which is the third to come from her ongoing five-year investigation into the education system's support for Maori.
It said the Auditor-General's staff saw a high correlation between schools using information effectively and better Māori student achievement, and those schools tended to have the most experienced leaders.
It also noted that "many of the schools operating in the most challenging circumstances had the least experienced leaders", and those staff needed support and mentoring.
"It is clear that there is a wide variation in practices between schools. In our view, this relates to variability in leadership, purpose, and the quality of practices for measuring performance and improving processes. There is significant potential for improvement through more consistent practices," the report said.
It recommended the Education Ministry investigate why Māori students' results varied between apparently similar schools.
The report said the school sector was trying to improve its use of data about student achievement, but some school boards said they did not use data about student achievement.
"In my view, the education sector needs to commit to building the capability and capacity to use information effectively and efficiently to support and raise Māori students' educational achievement," Lyn Provost said.
The report considered more than 500 school charters and found that a quarter did not have achievement goals for Māori children.
It said having few Māori children was no excuse for not having such goals and the report recommended the Education Ministry work with schools to ensure they included them in their charters.
The report called for improvements in schools' collection of ethnicity data about their students.
It said it was difficult to know which initiatives were having the most impact on raising Māori student achievement and recommended that the Education Ministry analyse which programmes were providing the best value.
"Because it is using public money to fund these programmes and initiatives, the Ministry needs to work out how much they cost, whether they are effective, and whether they add any value overall and to Māori students in particular."
Education Ministry deputy secretary for early learning and student achievement Lisa Rodgers said it agreed collecting data on students' progress and using it effectively were critical to supporting improved Māori achievement.
She said the education system faced challenges, but improvements were happening.
"We are now seeing a significant positive shift in the participation and achievement rates of Māori students. More Māori children are participating in ECE (early childhood education) and more Māori students are achieving NCEA Level 2. This is the result of a deliberate and systemic focus on what makes the biggest difference for these learners."
Ms Rodgers said factors behind the improvement included the government's targets for student achievement, providing achievement information for iwi and school communities, and providing a range of approaches and supports for those at risk of underachieving.
"This report provides helpful insights on how the best schools use data, and the power of data to help schools raise achievement for Māori students.
"We fully support the call made in the report to increase and improve the collection and use of data across our education system, especially student achievement data. This has been a focus of action for the Ministry. Whilst we are making progress we acknowledge that we have more work to do in this area."