Health action process approach
A health-behavior model that splits change into a motivation phase and a volition phase, bridging the gap between intention and action.
What it means
HAPA models health behavior change as two ordered phases: a motivational phase, in which risk perception, outcome expectancies, and action self-efficacy combine to form an intention, and a volitional phase, in which planning, coping self-efficacy, and action control translate that intention into sustained behavior. Its central contribution is the explicit 'post-intentional' machinery — action planning and coping planning — that addresses the intention-behavior gap most predecessor models leave unexplained. It distinguishes people by stage (non-intenders, intenders, actors), so interventions can be matched to where a person actually is rather than treating motivation and action as one step. The framework is influential in public health because it operationalizes self-efficacy as phase-specific (action, coping, and recovery self-efficacy) rather than a single trait. Its nuance is also its cost: the full model has many constructs, and not every study finds each path, so applications often test reduced versions.
Examples
A patient intends to exercise after a cardiac scare (motivation phase) but only starts when a coping plan tells them what to do on rainy days and busy weeks (volition phase).
A smoker convinced the risk is real and quitting worthwhile is an intender; they become an actor only once they have planned what to do at the pub when the craving arrives.
Urging non-intenders to fear skin cancer is wasted on someone who already intends to use sunscreen — what that person needs is a plan that puts the bottle in the beach bag.
First described in Ralf Schwarzer (1992).