Educators and researchers predict New Zealand schoolchildren will do poorly in an international maths and science test that started in earlier in November.
They say there are clear signs their science performance will worsen, while improvement in maths hinges on the types of questions asked.
The Trends in International Maths and Science Study is run every four years.
Last time it was held, New Zealand students' maths performance was unchanged, but their science score was the worst since 1994.
The Education Ministry expects a similar or improved performance this time.
However, science educators and university researchers say national monitoring indicates that they will do worse in science.
They say maths results will depend on whether the test covers the same things that maths training for teachers has focused on in recent years.