Table 3 Internal consistency of measurement scales
From: Capability, opportunity, and motivation: an across contexts empirical examination of the COM-B model
Measure | Physical activity | Eating | ||
|---|---|---|---|---|
No. of items | α | No. of items | α | |
Perceived competence | 5 | .87 | 7 | .87 |
Decision making (pros) | 9 | .91 | 4 | .82 |
Decision making (cons) | 3 | .80 | 5 | .77 |
Action control | 5 | .91 | 6 | .88 |
Action planning | 4 | .95 | 4 | .89 |
Habits | 12 | .97 | 11 | .96 |
Subjective norms | 5 | .73 | – | – |
Injunctive norms | – | – | 3 | .85 |
Descriptive norms | – | – | 3 | .65 |
Social support | 10 | .92 | – | – |
Social support (negative) | – | – | 4 | .84 |
Social support (positive) | – | – | 3 | .87 |
Perceived environment (PA) | 5 | .85 | – | – |
Perceived environment (home) | – | – | 4 | .78 |
Perceived environment (shop) | – | – | 3 | .76 |
Perceived environment (work) | – | – | 3 | .82 |
Identity | 9 | .95 | 3 | .77 |
Self-efficacy | 3 | .90 | 3 | .87 |
PBC | 3 | .87 | 3 | .85 |
Attitudes (instrumental) | 3 | .89 | 3 | .80 |
Attitudes (affective) | 3 | .89 | 3 | .89 |
Intentions | 3 | .96 | 5 | .91 |
Goals (social) | 4 | .93 | – | – |
Goals (appearance) | 3 | .95 | – | – |
Goals (personal) | 4 | .89 | – | – |
Goals (eating) | – | – | 6 | .84 |
Goals (drinking) | – | – | 4 | .71 |
Reinforcement | 2 | .80 | – | – |
Reinforcement (control) | – | – | – | .82 |
Reinforcement (mind) | – | – | – | .91 |
Affect (positive) | 5 | .91 | 2 | .76 |
Affect (negative) | 5 | .88 | 4 | .83 |