Pukekohe High School final-year student Atarangi Thompson is in no doubt: physics is hard.
"Some subjects like English, maths and science are a lot harder mentally to understand," she says, after a lesson that included the equation for splitting the atom and having to explain why the energy lost in an atomic explosion is equivalent to the increase in mass.
But in our system the intellectual rigour of those subjects is not given greater value. "Demonstrate understanding of atomic and nuclear physics" is worth 3 credits at Level 2 of the National Certificate of Educational Achievement (NCEA). "Experience day tramps" is worth exactly the same.
"Walking can be hard physically," Atarangi says. "But this stuff - it's more that you need to learn more. I think that harder subjects should be worth a lot more credits."
A new report by the New Zealand Initiative, a business-funded think tank, says we have failed a generation of young people like Atarangi by giving them no incentive to extend themselves.
We have deluded ourselves into thinking we are doing well because students leaving school with at least NCEA Level 2 have increased dramatically from 58 per cent of school-leavers in 2005 to 80 per cent in 2016.
But in the same period our 15-year-olds' scores in global tests for the Programme for International Student Assessment (Pisa) have been sliding in all three subjects - reading, maths and science.
Using NCEA data, you would think the educational gaps between our socio-economic and ethnic groups have been marvellously closing. In the five years to 2016 the proportion of 18-year-olds with at least NCEA Level 2 leapt by 17 percentage points for Māori, and by 13 points for Pasifika, compared with only 9 points for Pākehā.
Yet in University Entrance (UE), which does not count non-academic subjects such as "Experience day tramps", the ethnic gaps have actually widened slightly since NCEA began in 2002.
The proportions of both Māori and Pasifika school-leavers with UE rose by 11 points from 2001 to 2016, compared with an average gain across all school-leavers of 15 points.
NZ Initiative report author Briar Lipson, who helped start several academy or charter schools in Britain before moving to New Zealand last year, quotes research by Herald journalist Kirsty Johnston, who found Māori and Pasifika students are disproportionately channelled into non-academic subjects such as hospitality and retailing.
"It is hard to avoid the suspicion that at least some of this apparent improvement is based on learning that is of dubious value," Lipson says in the report.
"To create a national assessment system that pretends all subjects - from meat processing to mathematics - are equal, is a deception, and one that falls hardest on the very students most deserving of protection.
"There is no magic bullet or shortcut to educational equity. But NCEA disregards this difficult reality and instead places a deceit at the heart of our national assessment by suggesting to children that filling plastic containers holds the same value as studying literature, physics or Te Reo."
NCEA defines "standards" for students to reach and encourages teachers to get all - or at least the vast majority - of their students up to those standards.
The official NCEA guidance from the NZ Qualifications Authority (NZQA) says: "Students should not be assessed for a standard until the teacher is confident that achievement of the standard is within their reach, or until the final deadline for assessment, if there is one."
If students still fail, they can be offered another assessment "after further learning has taken place".
All academic subjects, and a huge range of trades and other learning areas, have been broken down into chunks, or standards, which are mostly worth between 3 and 5 credits.
The number of credits for each standard is not based on how "hard" the subject is, but on time taken. In theory, each credit should need 10 hours of learning.
Lipson says the way NCEA is structured has made it "a perversion of the intention of any assessment".
A head of English at a provincial high school told her: "Many students can only produce the standard of work required on a one-off basis, and only because the teacher drags them 'over the line'. Give the student a similar task two months later and ask her/him to replicate the result independently, inevitably s/he can't."
This teacher explained to the Herald on Sunday that internal assessment requires teachers to be both "coach and referee". It's in everyone's interests - teacher, school, student and parents - for the teacher to pass every student.
"Say it's a piece of persuasive writing," he says. "The teacher teaches them the structure of the piece, might give them the topic.
"Essentially the teacher keeps polishing that work, and all of that can be classed as 'formative feedback', and only when the teacher is satisfied that the work is of 'achieved' standard should the student hand it in.
"If I teach a Year 11 boy how to write a five-paragraph essay stating cows shouldn't be able to urinate in the river, he can pass.
"But if I give them a different topic, say 'write to the Prime Minister saying housing prices are unaffordable', he can't. He can write that one single essay that you have given endless rounds of feedback on."
Lipson argues for two big changes to restore the system's integrity:
• Restore a "core curriculum" of English or Te Reo, maths, science and perhaps a social science or a language, which every student must take at least through Year 11, and put the separate "chunks" of learning back into whole subjects so that students can no longer pick and choose what they learn; and
• Abolish internal assessment and restore external exams in all subjects that can be examined externally, with questions that can't be predicted.
Her report is well timed. Education Minister Chris Hipkins has set up a wide-ranging review of NCEA, with a discussion document due out next month and recommendations for change due in September.
There is surprising consensus about much of Lipson's analysis. Post Primary Teachers Association president Jack Boyle says most teachers would support "all students continuing with English, maths and science and possibly a social science to the end of Year 11, maybe Year 12".
He also supports reducing internal assessment to reduce the burden on students and teachers.
But he says some internal assessment is still required to encourage learning projects that might span several subjects or standards.
"Don't call it internal assessment every two weeks," he says. "Move towards collaborative portfolio project-based learning where you cover the curriculum as best you can and hang the assessment off that learning experience."
David Hood, NZQA's founding chief executive in the years 1989-96 when NCEA was first conceived, says NCEA was intended to be a "leaving certificate" that summed up a student's whole school learning - not isolated chunks of learning to be "ticked off" like steps on an assembly line.
"NCEA has become the curriculum in schools. It drives what teachers teach and what students have to learn," he says.
"It leads to shallow and superficial learning. It creates workload stress for teachers and students. It is constraining and restricting. It's governed by myriads of rules that restrict innovation in schools. It has failed to address the issue of equity in our system."
Like Boyle, he agrees the number of standards to choose from should be reduced.
"I go further. I believe that in the core curriculum areas like science, we could develop a single standard and what we do is we assess students' learning in regards to whether it is level 1, 2 or 3," he says.
But Hood argues today's problems are interdisciplinary and the skills employers actually need, such as perseverance, creativity and teamwork, come from working in teams on projects that span multiple subjects. And he says that kind of learning is best assessed internally.
In a draft submission to Hipkins' review, he recommends abolishing all external exams, arguing they cannot measure everything a student has learned.
At Pukekohe High School, students taking outdoor education, which includes the "Experience day tramps" standard, argue what they learn on tramps and other outdoor activities such as mountain biking gives them skills that will be as useful in their lives as more academic subjects.
Heather Ineson, a Year 13 student who is taking biology, chemistry and statistics as well as outdoor education, aims to become a nurse.
"It's important to understand what can happen to your body, and risk management, and understanding how you can fix yourself," she says.
Patrick Butters, who is taking statistics, agriculture and business studies, says outdoor education has inspired him to want to work in environmental management.
"It has shown me what we have got here [in the New Zealand environment] and what we have to keep, rather than destroying it," he says.
Outdoor education teacher Tara Remington, an ocean rower who was the first New Zealander to row across both the Atlantic and Pacific Oceans, says outdoor education helps students to become well-rounded human beings able to assess risks, solve problems, work collaboratively and understand other people.
Her principal, Ian McKinnon, who retires this year after leading the school for 22 years, says the curriculum has become much broader in his lifetime and aims to prepare each student for their chosen future career.
"We are building houses here now [in technology courses]. It's about needs-based learning," he says.
Julia Brenchley, a British recruit who was teaching Atarangi Thompson's class on nuclear physics this week, says the broad range of NCEA keeps many more students engaged in learning here than in Britain.
"A lot of students are not academic and never will be, so things like outdoor education give them a chance to still do well, and the fact that you can get the same credits for things makes them important," she says.
"In the UK we don't have that same broad range of subjects, and that's a real shame. What we do have is not considered as important as the academic, and as a result we end up with a lot more disengaged young adults who don't have any qualifications at all."
At Hobsonville Point Secondary School, which has abandoned Level 1 of NCEA completely, principal Maurie Abraham says the focus is on "deep learning" through multidisciplinary projects that are relevant to the local community, with NCEA credits picked up almost incidentally along the way.
He says Lipson's proposals would shift our system towards those of exam-bound countries such as China and South Korea, which top the Pisa rankings - but those countries now realised they had to change.
"They are all coming to New Zealand to look at what they are doing wrong," he says.
"Is that what we want? Or do we want our kids to be deep thinkers, problem solvers, developing interpersonal skills and engaged in learning that involves them in connecting significant areas together to inquire into legitimate problems and issues of significance to them and the world?"
Tim Ti, a Chinese international student at Pukekohe High School, is also in Atarangi's physics class, but is happy students doing day tramps should get credits, too.
"Like me, maybe some people are into physics," he says.
"Maybe other people may be interested in doing more like exercise outside. That's fine, the credits are the same, because it depends on what people are interested in."