“…Some of the outcome research on adult sex offenders, which include a comparison group, has not even specified whether or not the participants were treatment volunteers (Hanson, Steffy, & Gauthier, 1993;Konicek, 1996;Ohio Department of Rehabilitation and Correction, 2001;Schweitzer & Dwyer, 2003;Zgoba, Sager, & Witt, 2003). In other studies, staff selected individuals among volunteers and there was no comparison group of nonvolunteers (Berlin et al, 1991;Dwyer, 1997). One study included two types of comparison groups but did not conduct any multivariate analyses (Mander, Atrops, Barnes, & Munafo, 1996).…”