NSW education minister Adrian Piccoli announced the biggest overhaul of the HSC in almost 20 years last week including curriculum changes, a crackdown on cheating and the introduction of a mandatory literacy and numeracy test.

Currently, to get their HSC, students need to complete the curriculum, submit assignments and sit exams, but from 2020 all students will have to meet the literacy and numeracy levels of proficient Year 9 students in order to receive it.

Next year, Year 9 students will have their first opportunity to meet this new standard by achieving minimum band 8 results when they sit NAPLAN. Those who don't, will need to pass an online test in subsequent years to meet the requirements.

"These changes will strengthen the integrity and international standing of the HSC and better prepare our students for work, training, university and for life after school," Mr Piccoli said.

But, local educators have warned against a focus on literacy and numeracy to the detriment of other attributes necessary for success, like problem-solving, creativity and technical proficiencies.

Murray Guest, headmaster of The Armidale School, said the general principle of wanting set standards for literacy and numeracy in the senior years of schooling was a welcome development, but the headline announcement of conditional awarding of an HSC raised some questions and concerns.

"For example, I wonder what purpose denying an HSC to a talented design and technology student who faces significant literacy or numeracy impediments serves?" he said.

"Enabling the abilities of all students is equally important as establishing standards for core literacy and numeracy skills and I look forward to seeing how this will be accommodated."

Dr Anne-Marie Morgan, deputy head of the University of New England's School of Education, said an indication of literacy and numeracy standards was good up to a point but to have it all weighing on just one test had its limitations, and she's a firm believer in recognising other skills that will help students get ahead in "the 21st century job market".

She said currently, only about 50 per cent of Year 9 students achieved a band 8 result.

Improving literacy and numeracy standards should be addressed by a more wholistic approach, Dr Morgan said, which would include more funding for schools via the six-year Gonski funding arrangements.

She said the evidence was there that disadvantage had a significant impact on students' NAPLAN results, something the needs-based focus of Gonski was designed to address.

NSW Teachers Federation acting president Gary Zadkovich welcomed the changes, but said a higher level of literacy and numeracy was reliant on the federal government honouring the full Gonski funding agreement in order for students to receive the support they needed throughout their schooling.