A Featherston school has pre-empted the Government's release of national standards data by uploading achievement results on the school's website.
But Featherston School principal Phil Robertson said he opposed the information being made public in the form of league tables to compare schools.
"It's ridiculous. If you're a wealthy school, or a high decile school you might have everybody above standard - but it doesn't show whether you are growing them or where they were at when they came in.
"If you were at a low decile school, you might have a high percentage of children below the standard, but you might have grown them ... It creates a false impression."
Teachers and schools have hit out at the release of national standards data, labelling the information "dangerous and misleading".
Mr Robertson said, far from withholding national standards data from the public, he made the information available on the school's website earlier this year.
Rather than trends pertaining to ethnicity, he found there were definite socio-economic factors at play.
Half the decile 3 schools students are Maori - a higher proportion than most other Wairarapa schools.
"There's definitely initiatives you can put in place, we're working on that, it's getting whanau involved in the school, it's making the school more relevant for those groups."
He questioned why national standards were being implemented in New Zealand when similar regimes had failed overseas.
The South Wairarapa Principals' Association said in a statement that parents should think twice before believing league tables of schools based on students' national standards results give a fair or accurate pictures of schools. "National standards cover a narrow range of skills in a narrow range of subjects, give little indication of a students' creativity and enthusiasm for learning, and have different interpretations and assessment practices from one school to the next."
The principals said standards measured the student population which comes into the school rather than processes in the school, and therefore comparisons between schools were invalid and meaningless.
NZEI vice-president Frances Guy said the teachers' union believed the data's release was part of the Government's push for partially privatised schools and charter schools.
The standards were clearly linked to privatisation and profit-making, she said.
"We're disappointed that they've been released in a form in which they will be used for league tables which will be very disruptive to education in New Zealand. If there is an issue about not having good enough reporting on individuals then that needs to be dealt with, but standards isn't the way to do it."
The controversial national standards policy for reading, writing and maths was introduced by National last term. It was met with resistance from teacher unions, principals and boards of trustees, with some schools boycotting the system.
Releasing preview data on Friday, Education Minister Hekia Parata said the standards set a baseline for learner achievement.
"Our Government introduced national standards to raise achievement, to identify children who are behind, to help parents help their children, and help schools to focus on what they need to do."
The data shows that nationally, 72 per cent of students in years 1-8 reached or exceeded the national standards for maths, 76 per cent reached or exceeded the standard for reading, and 68 per cent reached or exceeded the standard for writing.
Forty-two per cent of Maori are below or well below standards in writing, 34 per cent in reading and 38 per cent struggling in maths.
Up to 46 of Pasifika students are not meeting standards across all three disciplines.
Ms Parata said the data gave the Education Ministry the opportunity to better target Maori and Pasifika students.
"Doing everything the way we've always done isn't going to work."
All of the national standards data is set to be released on the Education Counts website this Friday.
Of the 2087 schools required to report against the standards, 1899 schools have submitted their data to the Education Ministry, and 188 schools are either yet to submit or have incomplete data.