The Education Minister has defended national standards despite an independent report finding teachers are ranking children's reading, writing and maths correctly only about 60 per cent of the time.
The report, commissioned by the Ministry of Education said teachers' use of the standards last year lacked dependability, Radio New Zealand reported.
The study was based on research involving 96 schools.
It said the proportion of poorly performing children who improved last year seemed unreasonably large.
Teachers' judgement lacked dependability and it was impossible to know how many of last year's national standards results were correct, the report said.