Submissions in the science category will need to show an evaluation of the experimental design and the data presented.
These can be shown in observational drawings, wall charts, web pages, and PowerPoint presentations.
Development is the key concept in the technology category and can be presented as computer programming or a website which would include an appropriate database.
A team of judges will crown the winners of the fair who are competing for a prize pool of $5000.
They will be looking for originality in projects or an original approach to a problem.
Judging will take place tomorrow from 8.30am to 1pm and the prizegiving will take place at 1pm the following day.
Members of the public will be able to get a glimpse of the scientific ideas at viewing sessions tomorrow and Friday at the Harvest Centre, Rotorua.
Niwa freshwater ecologist and science fair co-ordinator Tracey Burton said the fairs were an important way for students to think about and engage with science.
"For many young students, science fairs are the first time they will design and carry out their own scientific investigations," she said.
She hoped the experience would inspire them to pursue careers in the fields.
Niwa had provided major sponsorship for the fair, and others around the country, as part of a long-term commitment to enhancing science and technology for young Kiwis.
It was also sponsored by Kiwanis Club of Te Awamutu.
Niwa was also a sponsor of the Auckland City, South & East Auckland, Waikato, Canterbury, Westland and Wellington science and technology fairs.
Details of the event
When
: Thursday, August 15: 1pm - 5pm. Friday, August 16: 9am - 2pm.
Where:
The Harvest Centre, Rotorua