Wellington College principal Roger Moses, pictured on his school's new artificial pitch in 2012, says boys 'respond better to a more traditional examination'.

NCEA is better suited to girls, two boys' school principals believe.

An analysis of NCEA results since 2004 shows the pass rate for boys at NCEA level 1 has increased by 21.3 percentage points to 81.1 per cent last year.

But girls are still doing better. Last year, 87 per cent of girls passed level 1.

SCHOOL REPORT: What are the NCEA results at your school? See data for every school in New Zealand



A gender gap also persists at levels 2 and 3, and boys are falling even further behind girls when it comes to merit and excellence endorsements at these levels.



Only in scholarship examinations, where the country's very top pupils are assessed, boys are doing equally as well, if not better than girls.



Every year for the past three years, nine of 10 pupils to achieve premier awards for their results - which come with a $30,000 prize - have been male.



Michael Irwin, a senior lecturer in education at Massey University who specialises in boys' education, said: "If you look at the top scholarship achievements for 2014, most of them are young males. But then if you look down at the other end of the scale, you have a huge number of boys that are just not achieving anything."



Wellington College headmaster Roger Moses said at the very top end, boys were "absolutely thumping girls".



Pupils at the decile 10 boys' school consistently did well in the scholarship exam, an achievement he put down to the school's "unashamed" focus on competition.

"I suspect that boys do respond better to a more traditional examination, because it's a very immediate challenge," Moses said.

"I think it could well be argued that perhaps NCEA would seem to favour girls. There is something so consistent about it over the years that there needs to be an answer."

Peter Meecham Auckland Grammar headmaster Tim O'Connor wants parental donations made compulsory.

At Auckland Grammar School, a decile 9 boys' school, the majority of pupils are encouraged to sit the Cambridge International Examinations.

NCEA removed the ability for students to compare results and compete with their peers, headmaster Tim O'Connor said. Under the school's Cambridge system, boys are given a ranking in both their class and year level, which acted as a motivator to do well, he said.

"Young men enjoy competition. The model we operate is basically replicating what happens in sport, and we've just transferred it into an academic system."

READ MORE:

* NCEA results: Full coverage

* NCEA's gender gap - by the numbers

* Does NCEA get you a job?

Irwin said NCEA required a high level of literacy, a skill that boys were traditionally weaker in than girls.

"If you struggle in that area, NCEA is very difficult for you to achieve. It's very much a strong language-based examination programme," he said.

"The boys might have the knowledge but they don't have the language to put it down in NCEA."

The key to closing the gap was good teaching, Irwin said.

"We can pick NCEA apart as much as we like but it's here, it's what we've got, and therefore we've got to work with it, rather than saying no, it only suits the girls, it doesn't suit boys.

"We've got to look at what is the best way to prepare boys for NCEA."