“…For example, studies have applied the VFI to volunteerism in youth sports (Kim, Zhang, & Connaughton, 2010) and environmental conservation (Wright, Underhill, Keene, & Knight, 2015). Others have validated the instrument for use among particular demographic groups, including American (Francis, 2011), Chinese (Wu, Lo, & Liu, 2009), and Australian university students (Hyde & Knowles, 2013), as well as for older adults (Okun & Schultz, 2003; Okun, Barr, & Herzog, 1998) and retirees (Brayley et al, 2014). Similar to Clary et al (1998) other validation researchers have found issues with individual items and the overall factor structure of the VFI.…”