Table 1.

ABCD matrix of two of the causal-structural chains comprising Active plus.

Behavior change principles	Conditions for effectiveness	Applications	Sub-determinants (change objectives)	Determinants	Sub-behaviors (performance objectives)	Target behavior
Self-monitoring	The monitoring must be of the specific behavior (i.e. not of the physiological state or health outcome). The data must be interpreted and used. The reward must be reinforcing to the individual.	Self-complete logbooks to monitor own physical activity behavior in last week.	Older adults list the personally relevant benefits of being sufficiently active	Awareness	Older adults indicate reasons to be physically active as recreation	Initiate recreational physical activity
Tailored feedback and argumentation	Feedback needs to be individual, follow the behavior in time, and be specific.	Computer-tailored feedback in text on perceived positive and negative consequences of physical activity. New arguments to change opinions are provided in text.	Older adults express a positive attitude about being sufficiently active	Attitude	Older adults indicate reasons to be physically active as recreation	Initiate recreational physical activity

Note. The entire ABCD matrix can be found in the Open Science Framework repository at https://osf.io/epbm4/