After defining the domains to be explored, developing and pilot testing the questionnaire, decide which type of parents you will be focusing on and then select your sampling frame:

1) Parents of babies: conduct interviews (random or consecutive) among parents using well-baby clinics, maternity wards or examine the perinatal collection and follow-up.

2) Parents of sick children: data can be gathered from paediatric hospital services, or the hospital register for retrospective follow-up.

3) parents of pre-school or school age children:approach school principals, child care centres, and after-school care facilities to access parents. You could send the questionnaire home with the kid and have it returned the following day.

4) Parents of children with physical or mental disabilities: if you manage to get ethics approval to access the cases, or build partnerships with relevant government or clinical services, the questionnaire could be administered by the service providers.