Educators have dismissed Government figures on national standards results showing students are doing better in reading, writing and maths.
The figures published on Tuesday show slightly more children were judged to be at or above the standards last year than in 2011.
Some 77% of children in primary and intermediate schools were at or above the reading standard for their year level in 2012, while in maths the figure was 74%, and in writing 70%.
The figures are between 1.2 and 2 percentage points higher than in 2011, the first year schools reported their results. Education Minister Hekia Parata said the change is because students are doing better.
"In other education jurisdictions where, for instance, a national test has been introduced, there's been a significant difference between the first year and the second year. The increase we see between last year and this year, it's been an incremental change of 1.2 percent, 1.4 percent. So seeing this consistency is very reassuring."
But Principals Federation president Phillip Harding dismissed Ms Parata's comments.
"The claim by the minister that ... 1 percent here and there represents an improvement is frankly ridiculous.
"The standards are not national, they are not standard and teachers are still interpreting them in completely different ways from one end of the country to the other. To then come out and say that it represents progress is either mischievous or it's uninformed."
Professor Lee believes the increase was because teachers were concentrating on things that gave students high scores in tests to help decide if they had met a standard.
Education academics have described Ms Parata's claim as dangerous, not credible and very optimistic. They say teachers are still learning how to use the standards and it is too soon to draw any conclusions from the results.
Howard Lee, head of educational studies at Massey University, says the latest results don't show that students are doing better in reading, writing and maths.
"That isn't a credible claim. Essentially, what we'd be wanting to look for is long-term improvements over at least five to 10 years. I mean, it's natural over a year or two that a 1.2 to 2 percent increase is interesting, but I think that the key point really is, no I don't think the data is robust at this point."
The Labour Party's education spokesperson said national standards would not continue in their current form if the party is elected in 2014. Chris Hipkins said the results published on Tuesday are unreliable.