Students could be pushed into subjects which guarantee passes if achievement data is used to help judge whether the government needs to take over a school, the Green Party says.
Greens co-leader Metiria Turei said the use of student achievement data to help flag the need for possible interventions would have negative consequences.
Ms Turei said schools in poor areas would scramble to get their kids to pass national standards and NCEA, "no matter the cost".
"Poverty is linked to lower academic achievement so lower decile schools will need to spend a great deal more energy funnelling kids into subjects that will guarantee passes."
Education Minister Hekia Parata yesterday downplayed the significance of her earlier statements that the Government's new focus on achievement data would help it know when to step in if learning was suffering. Such interventions - where powers are taken away from a board and put in the hands of a commissioner or statutory manager - are currently triggered by major staffing, safety, or financial issues.
Ms Parata said student achievement data would not be the sole reason a school could face an intervention.
"Now that we have a better data and information basis for understanding learning and achievement, we are together with [Education Review Office] reports able to make an earlier assessment as to which schools require support and more precisely, what kind.
"All these decisions are weighed very carefully and are never based on one factor alone."
Ms Parata said the Government's focus was on helping schools to understand their own data, and the available support.
Yesterday the education union NZEI said the change could be problematic given the unreliability of achievement data, particularly national standards.