The Green Party is warning that information about standards in primary schools is unreliable.
Education Minister Hekia Parata released the first set of national standards data for primary schools on Friday which showed 76 per cent reached, or exceeded, the national standard for reading, 72 per cent for maths and 68 per cent for writing.
On Saturday, Fairfax Media published data it compiled for more than 1000 individual schools.
Green Party education spokeswoman Catherine Delahunty said treating education as if it was a competitive sport was not the way forward.
"Schools throughout New Zealand are tackling complex issues, many relating to wider socio-economic problems. Some schools are achieving amazing results that are not captured in the way the national standards data is collated."
The publishing of standards failed to take the wider issues into account, she said.
"The government's ideological policies and the desire by some in the media to come up with ranking systems will harm the long-term educational prospects of our children."
New Zealand Educational Institute national president Ian Leckie said the decision by Fairfax to publish their own version of data extracted from schools' annual reports was a business decision for a media organisation.