Glossary
COM-B components
What are the COM-B Components?
COM-B is a behavioral model stating that behavior (B) results from the interaction of three necessary conditions: Capability (C), Opportunity (O), and Motivation (M). The model directs attention to their interaction; identifying a category of influence is a starting point for investigation, not a complete prediction.
The Three COM-B Components
COM-B sits at the center of the Behavior Change Wheel. Each component has two parts:
- Capability: physical capacity, such as skills, strength, and stamina; and psychological capacity, such as knowledge, memory, and attention.
- Opportunity: physical conditions, such as time, resources, and access; and social conditions, such as norms and interpersonal influences.
- Motivation: reflective processes, such as plans and evaluations; and automatic processes, such as impulses, emotional reactions, and habits.
The framework uses these distinctions to investigate a specified behavior before selecting an intervention.
COM-B Model Example: Clinic Access
Suppose people want a flu shot and know how to get one, but the clinic closes before they finish work. The barrier described here is physical opportunity: the service is unavailable when they can attend. Evening clinic hours could address that access barrier. Whether they increase vaccination would need to be measured.
Why it matters
COM-B directs attention beyond information and persuasion. If access is the problem, another awareness campaign may miss it. The categories help organize the investigation; they do not guarantee that the team has found the cause or selected an effective intervention.