Leaving Cert students opting to do a written exam won't know what their calculated grade would be before sitting the paper.
But they'll be given the higher of the two scores when it comes to working out their CAO points.
A timetable for the exams will be published today.
Education Minister Norma Foley says students will be presented with a choice.
However the ASTI says it is bitterly disappointed the predictive grading only model won't take account of coursework or projects completed.
President of the teachers union, Ann Piggott, says there are issues with the process
Daina Moorehouse On The Brink Of Medal After Two Victories In Brazil World Cup
Wicklow Households Encouraged To Explore Grants To Lower Energy Bills
New Equipment To Support Disabled Water Sports Users In Accessibility Boost For Bray Harbour
Dominant Daina Moorehouse Into World Cup Last 16 After Opening Brazilian Bout
Greystones E-Bike Scheme Flourishing With Over 12,000 Recorded Trips