New research offers a unique solution to arrest the decades-long decline in Australian high school students selecting science subjects: tackle it like a marketing problem.

Tracey-Ann Palmer says her study on how students choose or reject science subjects in year 10 suggests they could be encouraged to choose those subjects if they were marketed better, emphasising the benefits of science skills for future jobs as well as everyday life.

Across the state, year 10 students are in the midst of selecting the subjects they will take in senior school.

But over the past 20 years there has been a significant drop in the proportion of students selecting science and maths, prompting recent calls by the Education Minister Christopher Pyne to make the subjects compulsory.

Ms Palmer said traditional attempts to attract more students to science - by making teachers and the content more engaging - haven't succeeded yet.

She wondered what if there was nothing wrong with science, but the issue was how kids saw science. "Then it becomes a marketing problem," she said.

As part of her PhD research, Ms Palmer held focus groups of year 10 and some year 11 students asking them about the factors they consider when selecting subjects. A survey of another 379 students then ranked the importance of these factors, such as whether they enjoyed the subject, whether it would be useful for their career or could get them good marks.

"First they made an emotional choice on whether they loved or hated a subject," said Ms Palmer, from the University of Technology, Sydney.

Students then made more practical decisions about how their subjects would fit with their career and university aspirations. When they decided to reject a subject the strongest determinant was that they perceived it as boring.

Ms Palmer, a trained science teacher, who also spent about a decade in marketing, said students appeared to assess how "valuable" a particular subject was, in terms of their enjoyment and their career or university plans, and compared those values to their other subject options.

She said science was considered an expensive purchase given the amount of time students felt they needed to invest in the subject to get good results. And few students could identify the benefits of studying science to develop skills such as critical thinking skills, which are useful for many jobs.

But Ms Palmer, who will present her results at conference in July, said there were several simple marketing strategies schools could trial to promote science subjects, such as explaining the values of critical thinking to many professions, not just science jobs.

Significant government funding has been used to increase the number of students taking science and mathematics in schools by improving teaching. The science curriculum has also been updated recently.

But science education academic Terry Lyons said the drop in high school science participation had coincided with an expansion in the number of subjects in senior school and the decision by universities to remove prerequisites from many courses.

"These are systemic changes and I think they have more explanatory power than anything else," said Dr Lyons, from the Queensland University of Technology.

As long as those factors are still in place participation rates will never go back to where they were in the 1990s, he said.