“…This is an important issue, because programs have been shown to be more effective when they are based on theory and evidence (Albarracín et al, 2005;Bos, Schaalma, & Pryor, 2008;de Bruin et al, 2010;Mullen, Green, & Persinger, 1985;L. Peters, Kok, Ten Dam, Buijs, & Paulussen, 2009;van Achterberg et al, 2010;van Empelen et al, 2003).…”