The transtheoretical model, often called the stages-of-change model, was designed to describe the stages people go through when changing behaviors. The stages described by the model are:

• Precontemplation - when the person has no intention to adopt (and may not even be thinking about adopting) the recommended protective behavior;
• Contemplation - when the person has formed either an immediate or long-term intention to adopt the behavior but has not, as yet, begun to practice that behavior;
• Preparation - when there is a firm intention to change in the immediate future, accompanied by some attempt to change the behavior;
• Action - when the behavior is being consistently performed but for less than 6 months; and
• Maintenance - the period beginning 6 months after behavior change has occurred and during which the person continues to work to prevent relapse.

The stages-of-change perspective is important because it recognizes that people are at different stages of readiness when it comes to using condoms or making other changes. Individuals at different stages may be receptive to different types of intervention messages. Clearly, a different strategy is necessary when one is dealing with someone who has no intention of changing his or her behavior than when one is dealing with someone who intends to change but has not been able to act upon that intention. Similarly, someone who is trying to change but has not been able to consistently perform the protective behavior requires a different message or strategy than someone who is consistently performing the behavior. The stages-of-change model suggests that rather than viewing behavior as an "all or nothing" phenomenon, it is important to view behavior change in terms of a sequence of steps and that interventions should be tailored to the stage that an individual is in.

The AIDS Community Demonstration Projects developed risk-reduction messages that were appropriate for each local community. Data collected as part of the study were used to determine the proportion of people in the various stages of change, and thus the types of stories that were needed.

Additional information about the transtheoretical model can be found in the following publications:

Prochaska, J. O., & DiClemente, C. C. (1992). Stages of change in the modification of problem behaviors. In m. Hersen, P. M., Miller & R. Eisler (Eds.), Progress in behavior modification (Vol. 28, pp. 184-218). New York: Wadsworth Publishing.

Prochaska, J. O., DiClemente, C. C., & Norcross, J. C. (1992). In search of how people change: Applications to addictive behaviors. American Psychologist, 47, 1102-1114.