Treatment expectancy as a function of the amount of information presented in therapeutic rationales

This study investigated the effects of content and formal variables in therapeutic rationales on treatment expectancies. Five treatment descriptions were presented to undergraduates (N = 250). The rationales varied in terms of therapeutic focus, number of techniques, and the length of the description. There was no support for the influence of therapeutic focus on expectancies. One of the treatment descriptions raised greater expectancies than the control condition. The effects appeared to be due to the moderate length or amount of information in the rationale. Findings are explained in terms of the perceived clarity of the information and the adequate description of the treatments presented.