Distrust is slowing the uptake of a computer system that will make the national standards in reading, writing and maths more accurate, groups representing teachers and principals say .
The government has spent $7.89 million on the Progress and Consistency Tool (PaCT), which helps teachers decide whether children have met the standards.
It was launched a year ago, and the Ministry of Education says 295 schools have signed up to use it.
The president of the Principals Federation, Iain Taylor, said that was not a good rate of uptake and distrust was stymying adoption of the tool.
"The history of national standards and the way that was enforced has created an issue with PaCT, which could be a good tool. So I don't know that people are necessarily disagreeing with what PaCT can do, it's about the way it could be used because of the feelings about national standards."
Mr Taylor said the Principals Federation opposed the tool.
He said it would boost confidence in the accuracy of schools' results and that would be a mistake because schools could record results arrived at by cheating or taking shortcuts to reach the official teacher judgement (OTJ) about a child's achievement.
"There are stories about that, where an OTJ in some places is made by one standardised test or two tests, and that's it."
Educational Institute (NZEI) president Louise Green said the union was against the tool because it would make the national standards even more important.
"It embeds a flawed process, a flawed model, even further and we know that our teachers and our principals don't like labelling children, they don't like seeing children as lacking really early on in their learning journey."
Louise Green said teachers were also worried about what the information would be used for.
"If the information is used to fund schools on performance, or fund teachers on performance, that's a very narrow indicator of what is a good school."
Teachers using system respond positively, says ministry
But the ministry's deputy secretary for early learning and student achievement, Lisa Rodgers, said it will not use the results to punish schools.
She said the ministry already had a lot of information about individual students from a variety of tests and assessments, and it did not misuse it.
She agreed it would be possible for schools to enter shonky national standards results, but said that could happen now and there was no evidence that schools were cheating.
Ms Rodgers acknowledged there was reluctance to use the new system, but said teachers just needed to give it a go.
"I don't know of any teachers actually who've seen the framework that haven't responded positively. They really get into it really quickly and they love it. Its saving them time, it's giving clarity about the progress we expect of students, it's giving them a shared language they can use across teachers."
Lisa Rodgers said the system helped teachers with a lot more than just their national standards judgements. It helped them understand the curriculum, children's progress, and the next things they needed to teach a particular child.
She said uptake of the tool was steady rather than slow and a further 280 schools had expressed interest in using it.