“…This is shown in manifest behaviour, (a) by his or her willingness to attend the follow-up examination at all six months later, and (b) by his or her development of plaque, calculus and gingivitis over the same period. As we have argued in another report (Camner et al, 1994) there is a long and well-reasoned research tradition of both attendance and oral health as indicators of compliance (Dubinsky, 1986;Duda, Smart & Tappe, 1989;Fishbein & Stasson, 1990;Gilbert & Maxwell, 1987;Horowitz, 1978;McCaul, Bakdash, Geboy, Gerbert & Tedesco, 1990;Tedesco, Keffer, Davis & Christersson, 1992;Weinstein e t al., 1989;Wells, McDiarmid & Bayatpour, 1990;Zoega, Barr & Barsky, 1991).…”