“…Participants might be regarded as vulnerable when personal, situational, and structural issues impact on their ability to volunteer for research without undue influence (Rogers, 2005). This is more likely to occur in emergency situations, with participants in institutional settings or undergoing medical treatments, and with disadvantaged groups, such as the poor or socially excluded (Cain et al, 2003;Rogers). Examples of recent studies in which researchers defined their participants as vulnerable include mental health service users (Tee & Lathlean, 2004), Latino adolescents and their families (Zayas, 2009), Hispanic drug users (Singer et al, 2008), and families of children with life-limiting conditions (Stevens, Lord, Proctor, Nagy, & O'Riordan, 2010).…”