Testing 40 predictions from the transtheoretical model

Sensitive measurement of behavior change requires dependent measures that a re sensitive to the whole spectrum of change, not just a single aspect of c hange. Traditional outcome variables such as point prevalence for smoking c essation focus on a single discrete event and ignore all other progress. Al ternatively, the criterion measurement model (CMM) is an approach that posi ts a three-construct outcome model (habit strength, positive evaluation str ength, and negative evaluation strength), where different constructs are se nsitive to change for different aspects of the temporal domain. In this art icle, a series of 40 differential a priori predictions were tested using a large representative sample of smokers. The focus was on the prediction of specific effect sizes rather than statistical significance. A series of com parisons involving stage transitions was examined using five variables repr esenting the three CMM constructs. The predictions involved movement from o ne of three initial stages (pre-contemplation, contemplation, and preparati on) to stage membership 12 months later. Thirty-six of the 40 predictions w ere confirmed, indicating that the outcome model has strong construct valid ity and accurately reflects movement between the stages of change. (C) 1999 Elsevier Science Ltd.