Students will face more emphasis on exams and less on internal assessment in changes to the NCEA system unveiled today.

There will also be a sharper focus on literacy and numeracy skills.

The Government's final decisions on reforming the National Certificate of Educational Assessment (NCEA) will increase external assessment for all achievement standards from 30 per cent now to a standardised 50 per cent across all subjects - even those that have traditionally been fully assessed internally such as Physical Education.

It will also radically streamline the structure of NCEA so that each student will sit five to six subjects a year, each worth 20 credits, for a maximum possible 100 or 120 credits.

Sixty credits will earn an NCEA, down from 80 at present - but students must also achieve 20 credits in literacy and numeracy as a "co-requisite" for NCEA which they will be able to achieve at any time from Year 7 onwards, well before the main NCEA assessments start in Year 11.

The reduced credit requirements are intended to stop students and teachers wasting time on building up and marking massive credit surpluses.

Lynfield College student Emily Gossen said she tried for 200 Level 1 credits in Year 11 even though she only needed 80.

But they represent a sharp shift back to the rigid subject-based systems of School Certificate and University Entrance that existed before NCEA was introduced in 2002.

The system will still include the opportunity to take "unit standards" in vocational areas such as trades, which accounted for just under a fifth of all NCEA standards assessed in 2017.

But "achievement standards", which made up the other four-fifths of the standards assessed in 2017, will be grouped into 20-credit subjects in which half of the standards will be internally assessed and the other half externally assessed.

The new structure appears to leave no room for extras, such as driver's licences or first aid courses, which many schools encourage students to take on top of their main subjects to get them over the NCEA pass mark each year.

The changes, announced by Education Minister Chris Hipkins at Mana College in Porirua this morning, are a dramatic lurch in the opposite direction from proposals released a year ago by a ministerial advisory group, which proposed abolishing external exams at Level 1 and substituting 20 credits for literacy and numeracy and 20 credits for a project of the student's choice.

The advisory group also wanted to allocate 20 credits out of 80 required for each of Levels 2 and 3 to "pathways opportunities" such as projects and internships.

Those proposals have been completely abandoned after an outcry from principals of traditional schools such as Auckland Grammar.

Hipkins quickly agreed to set up a "professional advisory group" of principals chaired by former Wellington College headmaster Roger Moses to "work alongside" the ministerial advisory group.

Both groups gave him separate reports early this year, but Hipkins said the two groups "ended up in the same place".

"When I sat down and read both reports, they were saying the same stuff. That was really promising because it meant we were reaching out and getting that degree of consensus," he said.

As expected, the final decisions include the ministerial advisory group's proposal to abolish the $76 fee now paid by parents for their children to sit NCEA each year, a cost that will be funded in the Budget due on May 30.

The new 20-credit "co-requisite" literacy and numeracy requirement will also be tightened, as proposed last year, to ensure that students reach a "common benchmark" in these basic skills. The current system allows them to get these credits through a large number of other subjects that have been assumed to require writing or maths skills.

But last year's proposals to reduce "fragmentation" of learning by "chunking up" units of learning into bigger chunks each worth more credits has been transformed in the final decisions into an effective return to more rigid traditional subjects.

A chart in the decisions document shows that each 20-credit subject will be broken down into four units or standards, each worth 4, 5 or 6 credits, instead of the current range of between 2 and 8 credits.

Half of those 20 credits for each subject - either two 5-unit standards or one 6-unit standard plus one-unit standard - will be internally assessed. The other half will be externally assessed.

"Achievement standards assessed externally will include exams and other forms of assessment, including portfolios," the document says.

The key difference is that the exams or portfolios will be examined by people outside the students' schools, reducing the inherent conflict of interest that teachers face with internal assessment where they have to be both advocates for each student and unbiased judges of their work.

The system will also be tightened to allow assessments to be resubmitted after correcting minor errors only to "achieve" a standard. Some schools have been allowing re-submissions to get upgrades to "merit" or "excellence", and that will now be banned.

However, students will still be able to re-sit any assessments completely after doing further learning.

The changes include a nod towards recognising alternative, non-academic pathways by introducing a new "Vocational Entrance" (VE) award alongside University Entrance (UE) at Level 3 in Year 13.

A VE will "signal that a student has undertaken foundational tertiary learning valued by industry, employers and tertiary education organisations and is ready for direct entry into higher-level vocational education and training".

UE will continue to be awarded to students who "gain sufficient credits from the list of UE-approved NCEA subjects to meet the requirements for entrance to university."