There can be a risk of bias with this method, for example some stakeholders may be more or less willing to participate in a focus group than others.
Gall fod risg o ragfarn gyda'r dull hwn, er enghraifft efallai y bydd rhai rhanddeiliaid yn fwy neu lai parod i gymryd rhan mewn grŵp ffocws nag eraill.