Our purposive sample strategy is designed to reflect the diversity of Gypsy/Traveller populations living in the UK. We aim to recruit mothers who live in permanent housing, and in authorised and unauthorised sites, and those following a nomadic lifestyle. Where the mother wishes, we will include other family members in interviews Health practitioners will be recruited purposively to include those working in maternity, early years’ and child dental health services. Finally we will include key informants from civil society organisations that are involved in community engagement activities with Gypsy/Travellers. See Table 1 for an overview of the proposed numbers of participants and data generation methods.Table 1Target numbers of participants in case studiesParticipantsData generation methodEach case studyTotal across four case studiesMothers of pre-school childrenFace-to face interviews8–1232–48Health and social care practitionersFocus group discussion6–824–32Telephone interviews2–48–16Key informants from civil society organisationsTelephone interviews2–48–16