As with the 2017 survey, the 2022 survey was designed to reduce non-response bias from candidates who were not elected by being available prior to the election.
Yn yr un modd ag arolwg 2017, cafodd arolwg 2022 ei ddylunio i leihau tuedd dim ymateb gan ymgeiswyr na chawsant eu hethol drwy fod ar gael cyn yr etholiad.