Some of the migrant communities living in Wales may be here in such small numbers that national surveys and data collections cannot gather a representative sample of experiences.
Efallai fod rhai o’r cymunedau mudwyr sy’n byw yng Nghymru yma mewn niferoedd mor fach fel na all arolygon cenedlaethol a chasglu data gasglu sampl gynrychioladol o brofiadau.