The Qualifications Authority has told MPs it could use artificial intelligence to help write school exams.
The authority appeared before the Education and Workforce Select Committee for its annual review on Wednesday.
NZQA wants more students sitting online digital exams rather than paper-based exams.
However, the authority's chief executive Grant Klinkum said some schools might struggle to provide enough computers to ensure all their students could sit an online exam at once.
He said with that problem in mind, NZQA could develop a bank of variations of each exam which could be offered on different days, rather than having a single exam on a single day for each subject.
Klinkum said writing exams took months, but artificial intelligence could help NZQA staff to develop variations of exams more quickly.
"We have about an 18-month process of developing very robust exam questions and you couldn't do that process five or 10 times, but you could do one set of original assessments and use AI to draft five or 10 variations which a human would then refine," he said.
MPs asked questions about last year's failures when the online exam system failed to cope with the number of logins.
Klinkum said NZQA had managed up to 13,000 logins to online exams for many years, but it had problems when logins exceeded 20,000 last year.
The vendor of the online exam system, Oxford-based company RM, was testing it to ensure it could cope with more users, he said.
"At the moment we have a version of the platform which they are testing at 45,000 simultaneous users. We think in our current operating environment that's too optimistic which is why we said to schools we're being very cautious about the May round of literacy and numeracy [tests], why we'd like them to stagger log-ons. So it is still two or three years away that we'll have real confidence that an English 1 exam with up to 45,000 students can be done without any staggering of log-ons," he said.
Klinkum said the authority was making sure exam centre managers knew what to do if there was a problem with online access.
"If tens of thousands of students are pushing the refresh button constantly it immediately overwhelms the system," he said.
Students should instead sit back for a minute before trying to log in again, he said.
Klinkum said 97 percent of students who sat digital exams said they were good or very good.
"Students expect to be able to have a spell check and be able to manipulate data as we all do as we do our work and really value the word-processing capability of digital assessment."
But he said students might struggle if they were not accustomed to using computers in the classroom on a regular basis.
Last year about 20 percent of total NCEA credits awarded to students were through external exams, with the remaining 80 percent attained through internal assessment, Klinkum said.
That meant quality assurance of teachers' internal assessment judgements was critical.
This year NZQA would moderate 57,000 examples of school-marked work to check that teacher judgements were accurate.