Following the change in definition announced in October 2023 persistent absence is defined as being absent for 10% of the most common number of required sessions.
Yn dilyn y newid mewn diffiniad a gyhoeddwyd ym mis Hydref 2023, diffinnir absenoldeb cyson fel absenoldeb am 10% o'r nifer fwyaf cyffredin o sesiynau gofynnol.