Critiques
- Conner and Armitage 2000
- Unable to assess the role of social cognitive variables in behavior change. TTM offers little insight into how behavior change is operationalized.
- Decisional balance is a crude measure with unclear links to other social cognition variables.
- The description of change is very global with limited insight into why some are successful in changing and how people change.
- The extent to which stages are mutually exclusive is unclear. There might be some pseudo-stages.
- There are limited empirical reports on the reliability and validity of stage classification measures.
- Limited empirical reports on the reliability and internal validity of stage classification measures.
- No study has reported that processes of change an decisional balance predict transition across stages of change.
- With dichotomous measures on past quit attempts, stages of change algorithm does not adequately capture stage assignment.
- Arbitrary temporal aspect of process classification may miss true classification which may need to be determined immediately (days or weeks) before stage change.
- Herzog 1999 and 2007
- Limited availability of qualitative case studies with a focus on practitioner and organizational use of the model.
- Strength of evidence-based may be exaggerated clouding the need to assess the utility of TTM to predict behavior change.
- In smoking cessation studies, TTM ignores other variables such as addiction level or quitting history, which may be important to behavior change.
- Stage processes and behavioral outcomes may be reciprocally determined.
- Stages assignment may miss individuals who are unassignable to stages of change or miss pre-precontemplative individuals.