Each Wales Omnibus survey is conducted with separate samples of Welsh adults 16+ which are quota samples in terms of demographics such as age, gender, region and social grade.
Wrth gynnal pob arolwg omnibws yng Nghymru, defnyddir samplau gwahanol o oedolion 16+, sy’n samplau cwota o ran elfennau demograffig fel oedran, rhyw, ardal a gradd gymdeithasol.