Western Bay principals say they have serious concerns about National Standards results being published on a Ministry of Education website.
Education minister Hekia Parata said national standards data, Education Review Office reports, school's annual reports and NCEA data will be made public next month.
The data release will be for literacy and numeracy only. The information itself will be published in the format in which the school submitted it.
Ms Parata said despite the information being variable, the purpose of publishing the data was to lift children's achievement and give parents quality information about different schools.
But local principals were concerned the information would be used to inaccurately compare schools.
President of Western Bay of Plenty Principal's Association and principal of Brookfield School, Robert Hyndman, said the information submitted from each school could not be compared.
"I think this is a real concern, particularly the misinterpretation of information and lack of consistency ... and I don't believe this will be helpful to parents. Unfortunately they might think it will be [beneficial] because on the face of it it looks quite useful but using this as a tool to compare schools, this doesn't mean a thing," Mr Hyndman said.
However, the country's largest advocacy group for enterprise and success, BusinessNZ, welcomed the release of school performance information.
BusinessNZ chief executive Phil O'Reilly said accessible information was essential to improving school performance.
"This new database is a good step forward for transparency in education," he said.
"Accountability for performance requires good information [and] a central database for information on school achievement, ERO reports and national standards data will make it easier for students, parents and others to monitor schools' performance."
Tahatai Coast School deputy principal Kristin Bell said the results would not reflect how much progress a child had made.
" Without all the information available and a lack of understanding about the value added, people are going to get a misguided view," Ms Bell said.
"Children with special needs are to be included in this but will never achieve at or above the standard so the starting point of a child and the progress they make should be celebrated, not whether they're achieving or not."
Other principals contacted by the Bay of Plenty Times said the release of the results would be damaging and misleading.
Greenpark Primary school principal Graeme Lind said there was more to schooling than reading, writing and mathematics. He said national standard results should not be published as schools used their own tools and teacher judgement to determine student ability.
"It's about the whole development of a child and I think this is becoming a very narrow perspective," Mr Lind said.
Education industry experts said the published information posed a potential threat to the privacy of individual students and teachers.