*2.1. Study Design*

A mixed-methods approach was used to collect quantitative and qualitative data from parent or caregiver/child dyads in playgrounds in Perth, Western Australia (WA). Trained researchers worked in teams of two to conduct covert, naturalistic observations (*n* = 85). In addition, intercept interviews were conducted with parents/caregivers (*n* = 20). The sample size for the observations was informed by naturalistic observational methodologies for data collection conducted in New South Wales, Australia (*n* = 50) [4] and New Jersey, US (*n* = 60) [27], whilst one other study in the US collected 171 observations over almost double (seven parks) [24] compared with four in this study. The sample size for the interview numbers (*n* = 20) were consistent with similar studies [4,27].
