Interviewers reported that overall the questionnaire worked well, with no major problems occurring during the field period.
Dywedodd yr holl reolwyr rhanbarthol fod yr astudiaeth beilot wedi gweithio’ n dda ac nad oedd unrhyw broblemau mawr o ran ffurflen yr arolwg, y deunyddiau i ymatebwyr, y systemau na’r prosesau.