The dumping of NAPLAN testing for 2020 is proving to be a mistake, say education experts, because it will leave schools without critical information on how far students have fallen behind during the pandemic.

Without a standardised national model for results, education departments and school principals don't have the full picture on what's been missed out, said the Centre for Independent Studies. And in the recovery phase it will be harder to measure what's been restored without a 2020 baseline.