Young participants aged 15 or below confirmed their assent, either by writing their name on an assent form or using stickers, depending on their age.
Cadarnhaodd cyfranogwyr ifanc 15 oed neu’n iau eu cydsyniad, naill ai trwy ysgrifennu eu henw ar ffurflen gydsynio neu gan ddefnyddio sticeri, yn dibynnu ar eu hoedran.