A new reporting system used to present NCEA statistics gives a more accurate outline than the system it replaces of how schools are performing.

National statistics were posted online at 5pm yesterday, giving pass rates as a percentage of NCEA participants rather than as a portion of the school roll.

Under the original reporting system, the percentage of students who passed levels 1 to 3 was up slightly on last year.

But the figure rose considerably when results were collated the new way.

For instance, 63 per cent of the Year 11 roll achieved NCEA level 1 last year, up 1 percentage point from 2007. But 70 per cent of all Year 11 students who participated, or could have participated in NCEA, passed.

The difference was more marked at top academic schools where most of the students sat Cambridge International Examinations.

Auckland Grammar School headmaster John Morris said the new reporting system was a positive move.

As a percentage of the school's roll, 27.8 per cent of Year 11 students passed level 1, 27 per cent of Year 12 students passed level 2 and 26.5 per cent of Year 13 students passed level 3.

But taking results only of boys who participated in NCEA, the pass rates were 66.1 per cent for level 1, 75.3 per cent for level 2 and 69.4 per cent for level 3.

"When you look at that we are pretty pleased with those sorts of results," Mr Morris said.

Byron Bentley, principal of Macleans College in Bucklands Beach, where 70 per cent of students select the Cambridge exams, also welcomed the change.

Under the old roll-based system, his school would have reported 23.5 per cent of Year 11 students passing level 1.

But yesterday's results showed 74.4 per cent of Year 11 NCEA participants passed that level - above the national average of 70.4.

"Our figures always looked a bit rough ... Now that it's accurate, it's as it should be," Mr Bentley said.

Qualifications Authority deputy CEO Bali Haque said the new statistics pages were developed after consultation with schools and would give more accessible and comprehensive information than the previous system.

The president of the Secondary Principals' Association, Peter Gall, said the previous system, which used a school's July roll as a denominator, was unfair because some students on a roll did not sit enough subjects to make up an NCEA qualification or left school before they sat exams.

"In the absence of anything else at the time it was thought to be the fairest way, but now what they have done seems to make a lot of sense to me," he said.

The roll-based figures are still available on the Qualifications Authority website so comparisons can be made with previous years, but Mr Gall said people still needed to take care when reading the statistics.

"NCEA data is still very complex, and there are a huge number of variables within the data, so unless people really understand them, they could easily make some wrong assumptions."

* 2008 results
Under the old system using roll-based statistics:

63 per cent of the Year 11 roll achieved NCEA level 1 (62 per cent in 2007).

66 per cent of the Year 12 roll achieved NCEA level 2 (64 per cent in 2007).

54 per cent of the Year 13 roll achieved NCEA level 3 (no change).

Using new participation-based statistics:

70 per cent of participating Year 11 candidates achieved NCEA level 1.

75 per cent of participating Year 12 candidates achieved NCEA level 2.

70 per cent of participating Year 13 candidates achieved NCEA level 3.