The school decile is not yet dead, but researchers are already thinking about how they will replace it with a new way of comparing schools and students from different backgrounds.
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School decile numbers are based on the percentage of students at each school that come from the most disadvantaged backgrounds.
They are used to allocate extra funding to tackle disadvantage, but also to monitor differences between rich and poor students and their schools.
The government, teachers and principals agree the decile ratings need to go, in part because the numbers are misunderstood by many people as an indicator of school quality.
Principals told RNZ's Insight programme the misunderstanding has helped drive down enrolments in low-decile schools, especially among Pakeha families.
This year the government is trialling an alternative approach, allocating $12 million to schools based on their enrolments by children who meet particular risk factors, such as parents who are long-term beneficiaries.
But if the decile number goes, how will researchers keep track of differences between students and schools with different socio-economic backgrounds?
The director of Massey University's institute of education, John O'Neill, said an alternative way of showing the background of a school's students was essential.
"If you ignore socio-economic circumstances of the school, you cannot possibly make fair judgements about the quality of learning and the quality of changes in learning or achievement by children," he says.
"You have to have some way of categorising and grouping schools according to the challenges that they face and also to be able to make broad comparisons about schools in the same circumstances. If you abandon that then you are not going to get anywhere."
Alison Gilmore is the co-director of the Educational Assessment Research Unit at the University of Otago and leads the National Monitoring Study of Student Achievement, which measures student achievement across the curriculum.
She said the targetted funding the government is testing this year could be used to group schools according to the percentage of their students that attract the funding. A similar system is used in the other countries based on the percentage of children receiving free school lunches.
Associate professor Gilmore said it was important people used the same measures of socio-economic status so their conclusions were comparable.
"If we've got different measures of it, people then tend to over-ride those contexts and make generalisations which are not appropriate. So if we are going to change the decile system we have to have a common understanding of what it is," she says.
Researcher Liz Gordon said if the government goes with a system of targetting, it should give researchers access to the information it gathers.
"I'd like to see whatever targetting system they have for funding available for us as reseachers to understand the social characteristics of schools so we can do our research," she said.
A senior researcher at the Council for Educational Research Charles Darr said alternatives include using census information or surveying children about things like the number of books in their homes.
He said more information about individuals rather than schools would be good.
"At the moment, when we've got the decile, that's an easy place to go, it gives us that school comparison, but it doesn't let us sometimes look at the much more nuanced things that could be happening within schools with particular groups of individuals who vary a lot in their socio-economic status."
Whatever system is introduced, it's likely schools with similar characteristics will be put into groups for ease of comparison.
Charles Darr said schools could be sorted into three or five groups for that purpose.
"We often find ourselves using five groups of schools and sometimes even three groups of schools to show the differentiation that can sometimes be associated with differences in socio-economic standing."
But Massey's John O'Neill said the decile system showed there were significant differences between schools so a larger number is needed.
"My preference would be for 10 or more groups, rather than three," he said.
Professor O'Neill said it should be public knowledge what group a school is in.
"Otherwise they're not able to make judgements about how well schools are doing in broadly equivalent circumstances."
But placing schools into different groups and telling the public which group each school is in raises the possiblity that whatever replaces the decile will simply introduce a new number or label that people can use as a proxy for quality.
Researchers said that would not be desirable, but Liz Gordon said it might be better than the alternative.
"What they might say in the future is 'all the troublesome children go there' or 'the kids of gangs go there'," she said.
"They'll replace if you like a measurement-based system with just general social discrimination."
The Ministry of Education said if the decile was replaced it would continue to analyse children's results, especially for those from disadvantaged backgrounds.