Table 2. Data collection strategy by research area/ question.

Area/ Question	Objective	Main data sources
Implementation: Is the pilot implemented as intended?	Assess whether the policy reaches eligible participants; the processes involved in enrolment; whether take up and throughput match expectations; the extent to which the Welsh Government’s ‘4 conditions’ for the pilot are met (see: https://www.gov.wales/written-statement-basic-income-pilot-care-leavers-wales)	• Focus groups with managers (n = 6) • Focus groups with government officials (2) • Focus groups with Young Persons Advisors (YPAs) (n = 6) • Administrative data from Care Leaver teams/ the Welsh Government
Experiences: How is the pilot experienced?	Understand the experiences of participants and professionals involved; the role of the BIP in participants’ lives; transitions into and out of the pilot; attitudinal and behavioural changes	Interviews with participants/ supporter dyads (n = 40/ 20) Focus groups with PAs (n = 6) Focus groups with foster carers and housing support workers (n = 2)
Integration: How does the BIP fit into the overall offer for care leavers in Wales?	Consider how the BIP sits alongside other forms of support, whether its introduction changes this support (e.g. makes other things less attractive or accessible)	Focus groups with managers (n = 6) Focus groups with PAs (n = 6) • Focus group with financial advisors (n = 1) • Senior professional interviews (n = 7)