What Is the Behaviour Change Wheel?
The Behaviour Change Wheel (BCW) is a systematic framework for designing behavior change interventions. It consists of three concentric layers: a diagnostic core (the COM-B model), a middle ring of nine intervention functions, and an outer ring of seven policy categories. Susan Michie, Maartje van Stralen, and Robert West at University College London developed the BCW. They published it in 2011 in Implementation Science and expanded it in the 2014 book The Behaviour Change Wheel: A Guide to Designing Interventions (co-authored with Lou Atkins).
Michie and colleagues built the BCW to solve a specific problem. They systematically reviewed 19 existing behavior change frameworks and found that none met all three criteria of usefulness: comprehensive coverage of all intervention types, coherent categorization (not mixing different levels of analysis), and linkage to an overarching model of behavior. They designed the BCW to satisfy all three.
The 2011 paper has accumulated over 15,000 citations on Google Scholar, making it one of the most cited papers in implementation science. The framework has been applied across healthcare, public health, education, workplace behavior, environmental sustainability, and pandemic response.
The Three Layers
Layer 1: COM-B (The Diagnostic Core)
COM-B states that behavior occurs when three conditions are present: Capability (C), Opportunity (O), and Motivation (M), which together produce Behavior (B). Each component has two subcomponents, creating six diagnostic categories:
Physical Capability. The physical skills, strength, or stamina needed. A person with limited mobility lacks the physical capability for a stair-climbing intervention.
Psychological Capability. The knowledge, cognitive skills, or mental capacity required. Healthcare workers who cannot remember the correct hand hygiene protocol have a psychological capability deficit.
Physical Opportunity. What the external environment provides: time, resources, locations, access, cues. No amount of motivation to exercise helps if the nearest gym is 30 miles away.
Social Opportunity. Cultural norms, social cues, and interpersonal influences. Whether colleagues smoke during breaks. Whether friends encourage or mock healthy eating attempts.
Reflective Motivation. Conscious processes: planning, goal-setting, evaluating pros and cons, forming intentions, identity beliefs.
Automatic Motivation. Processes that happen without deliberation: emotional reactions, desires, impulses, habits. The craving for a cigarette. The automatic habit of reaching for a phone.
COM-B is a dynamic system. Capability affects motivation (lacking a skill erodes confidence). Opportunity affects motivation (if healthy food is unavailable, intentions to eat healthily weaken). Behavior feeds back into all three (successfully performing a behavior builds skill, opens new social connections, and strengthens confidence).
Layer 2: Nine Intervention Functions
Once COM-B identifies why a behavior is not happening, the middle ring identifies what type of intervention to deploy. Each function addresses specific COM-B deficits:
| Intervention Function | What It Does | COM-B Targets |
|---|---|---|
| Education | Increases knowledge and understanding | Psychological Capability |
| Training | Imparts skills through practice | Physical + Psychological Capability |
| Enablement | Reduces barriers beyond education/training (e.g., medication, behavioral support) | Capability + Opportunity |
| Persuasion | Uses communication to stimulate action | Reflective + Automatic Motivation |
| Incentivisation | Creates expectation of reward | Motivation |
| Coercion | Creates expectation of punishment | Motivation |
| Environmental Restructuring | Changes the physical or social context | Opportunity + Automatic Motivation |
| Modelling | Provides examples to aspire to or imitate | Motivation + Social Opportunity |
| Restriction | Reduces opportunity for competing behaviors | Opportunity |
The authors drew precise distinctions between terms that overlap in everyday language. “Education” focuses on knowledge, not skills. “Training” focuses on skills, not knowledge. “Enablement” covers support that works through mechanisms beyond what education, training, or environmental restructuring provide (pharmacological support, behavioral counseling, prostheses).
Layer 3: Seven Policy Categories
Policies are actions by responsible authorities that enable or support interventions:
- Communication/marketing (mass media campaigns)
- Guidelines (treatment protocols, practice recommendations)
- Fiscal measures (taxes, subsidies)
- Regulation (voluntary agreements, industry standards)
- Legislation (laws, mandates)
- Environmental/social planning (town planning, infrastructure design)
- Service provision (establishing support services)
Each policy category maps to specific intervention functions. For example, “Service provision” can deliver Education, Persuasion, Incentivisation, Coercion, Training, Modelling, and Enablement. “Environmental/social planning” maps primarily to Environmental Restructuring and Enablement.
How to Use the BCW: The Eight-Step Process
Michie, Atkins, and West codified the process in their 2014 book. Three stages, eight steps.
Stage 1: Understand the Behavior
Step 1: Define the problem in behavioral terms. Not “people are unhealthy” but “adults aged 40-65 with type 2 diabetes are not performing 150 minutes of moderate-intensity physical activity per week.”
Step 2: Select the target behavior. List all behaviors that could address the problem. Score them on likely impact, likelihood of change, spillover effects, and measurability. Select 1-3 targets.
Step 3: Specify the behavior. Define who, what, when, where, how often, and with whom.
Step 4: Run the COM-B analysis. For each of the six subcomponents, assess whether it is a barrier. Use interviews, surveys, observation, or existing data. The Theoretical Domains Framework (TDF), originally published in 2005 with 12 domains (Michie et al., Quality and Safety in Health Care) and refined to 14 domains by Cane, O’Connor, and Michie in 2012, provides more granular diagnosis for complex behaviors. Its domains map onto COM-B’s six subcomponents.
Stage 2: Identify Intervention Options
Step 5: Identify intervention functions. Use the COM-B analysis to look up which intervention functions are relevant. A physical opportunity barrier points to Environmental Restructuring, Restriction, and Enablement.
Step 6: Identify policy categories. Determine which policies can support the chosen intervention functions.
At both steps, apply the APEASE criteria to shortlist options:
| Criterion | Question |
|---|---|
| Affordability | Can it be delivered at acceptable cost? |
| Practicability | Can it be delivered as designed in the real-world context? |
| Effectiveness | Does the evidence support it? Is it cost-effective? |
| Acceptability | Will the target population and stakeholders accept it? |
| Side-effects | What unintended consequences might occur? |
| Equity | Will it reduce or increase health inequalities? |
Stage 3: Select Content and Delivery
Step 7: Select behavior change techniques. Use the BCT Taxonomy v1 (93 techniques in 16 groupings, Michie et al., 2013, Annals of Behavioral Medicine) to specify the exact techniques that deliver each intervention function. Apply APEASE again.
Step 8: Select mode of delivery. Face-to-face versus distance. Individual versus group. Digital versus print. Apply APEASE again.
Real-World Applications
COVID-19 Pandemic Response
The BCW became the most widely used behavioral framework during the pandemic. The UK government’s Scientific Pandemic Influenza Group on Behaviours (SPI-B), of which Susan Michie was a prominent member, used COM-B to structure advice on mask-wearing, hand washing, social distancing, and vaccine uptake.
West and colleagues (2020) published “Applying principles of behaviour change to reduce SARS-CoV-2 transmission” in Nature Human Behaviour, using COM-B to categorize pandemic-relevant behaviors and map them to intervention strategies. The paper has been cited over 1,000 times.
Sherman and colleagues (2021) used COM-B to analyze vaccine hesitancy among 1,500 UK adults (Human Vaccines & Immunotherapeutics). Reflective motivation (beliefs about vaccine safety) was the strongest predictor of vaccine intention. Social opportunity (perceiving that friends and family supported vaccination) was second.
NHS Stop Smoking Services
Fulton and colleagues (2016) used the full BCW process to design StopApp, a smartphone application to increase uptake and attendance at NHS Stop Smoking Services, published in Healthcare. Gould and colleagues (2017) followed all three BCW stages to design a smoking cessation intervention for Australian Indigenous pregnant women (Implementation Science). Both studies demonstrated the step-by-step BCW process applied to real intervention design.
Workplace Sitting Reduction
Edwardson and colleagues used COM-B to design the “Stand More AT Work” (SMArT Work) intervention. The cluster randomized controlled trial across NHS offices reduced sitting time by 50 minutes per 8-hour workday at 3 months and 83 minutes at 12 months (Edwardson et al., 2018, BMJ). Follow-up research indicated effects were maintained over the longer term.
Sepsis Treatment Compliance
Steinmo and colleagues (2015) applied COM-B to understand why healthcare professionals did not follow sepsis treatment guidelines (Implementation Science). Social opportunity (team norms around escalation) and automatic motivation (confidence under pressure) were the primary barriers. The COM-B-informed training program improved sepsis bundle compliance from 24% to 42%.
Hand Hygiene in Healthcare
The 2014 BCW book uses NHS hospital hand hygiene as its primary running example. Greene and Wilson (2022) found in a scoping review (Journal of Infection Prevention) that the BCW was the most commonly used framework in infection prevention and control behavior change studies.
Limitations and Criticisms
Complexity. The full BCW process (3 stages, 8 steps, 6 COM-B subcomponents, 9 intervention functions, 93 BCTs, 7 policy categories, APEASE criteria at multiple stages) is labor-intensive. A thorough behavioral diagnosis requires qualitative research, literature review, and systematic COM-B coding. This can take weeks or months. Connell and colleagues (2019) surveyed 277 health psychology researchers and practitioners: while 72% had heard of COM-B, only 31% had used the full BCW process, citing complexity and time requirements as barriers.
Limited guidance on prioritization. The COM-B-to-intervention-functions matrix often identifies multiple relevant options for any given barrier. The APEASE criteria provide a principled way to narrow options, but they are qualitative judgments, not quantitative decision rules. Two teams applying APEASE to the same situation may reach different conclusions.
Tension between comprehensiveness and usability. The BCW’s stated advantage is comprehensiveness. But comprehensiveness creates cognitive load. Teams sometimes find the BCW overwhelming compared to EAST (4 principles) or Fogg’s B=MAP (3 factors), both of which are deliberately reductive and faster to apply. A government agency designing a national policy might benefit from the full BCW. A product team with a two-week sprint might not.
Does not predict effectiveness. The BCW guides intervention selection but does not guarantee the selected intervention will work. As the original paper states: “Research is needed to establish how far the BCW can lead to more efficient design of effective interventions.” This remains an open question.
Self-report dependency. COM-B analyses typically rely on interviews and questionnaires. This creates problems for automatic motivation (by definition hard to self-report) and physical opportunity (people may not recognize environmental constraints).
Cultural applicability. The BCW was developed in the UK by UK-based researchers. Fewer studies have validated it outside Western populations. Social opportunity norms vary dramatically across cultures. The framework has been applied in sub-Saharan Africa and Southeast Asia, but published cross-cultural comparisons remain limited.
BCW vs. Other Frameworks
| Framework | Purpose | Granularity | Usability | Best For |
|---|---|---|---|---|
| BCW | Full intervention design system | Highest (COM-B + 9 functions + 93 BCTs + 7 policies) | Low (requires training) | Health interventions, policy, research |
| COM-B | Behavioral diagnosis only | Moderate (6 subcomponents) | Moderate | Quick behavioral assessment |
| MINDSPACE | Behavioral audit checklist | 9 elements | Moderate | Policy design brainstorming |
| EAST | Practitioner design checklist | 4 principles | High (memorable) | Rapid intervention design |
| Fogg (B=MAP) | Product design heuristic | 3 factors | High (intuitive) | Product design, habit formation |
| BCT Taxonomy | Technique specification | 93 techniques | Low (requires training) | Intervention reporting, meta-analysis |
Many practitioners use these frameworks in combination: COM-B to diagnose, the BCW to select intervention types, the BCT Taxonomy to specify techniques, and EAST to check the design.
Frequently Asked Questions
What is the Behaviour Change Wheel? The Behaviour Change Wheel (BCW) is a systematic framework for designing behavior change interventions. It consists of three layers: the COM-B model at the center (diagnosing Capability, Opportunity, and Motivation barriers), nine intervention functions in the middle ring (what type of intervention to use), and seven policy categories in the outer ring (how to deliver the intervention). It was developed by Susan Michie, Maartje van Stralen, and Robert West at UCL and published in 2011.
What is the difference between COM-B and the Behaviour Change Wheel? COM-B is the diagnostic core of the BCW. COM-B identifies why a behavior is or is not occurring by assessing six subcomponents (physical and psychological capability, physical and social opportunity, reflective and automatic motivation). The full BCW adds intervention functions (what to do about it) and policy categories (how to deliver it at scale). COM-B diagnoses. The BCW prescribes.
How long does the BCW process take? The full eight-step BCW process, applied rigorously, can take weeks to months. Step 4 (COM-B analysis) alone requires qualitative research, data collection, and systematic coding. For rapid-cycle design or resource-constrained teams, many practitioners use a “light” version: running a quick COM-B assessment based on existing knowledge or a few key informant interviews, then selecting intervention functions and BCTs.
What are the APEASE criteria? APEASE stands for Affordability, Practicability, Effectiveness and cost-effectiveness, Acceptability, Side-effects/safety, and Equity. These six criteria are used at multiple stages of the BCW process to filter intervention options. They provide a principled way to narrow choices when the framework identifies multiple viable intervention strategies.
Is the BCW only for health behavior? The BCW was developed in a health context and most published applications are in health. The framework has also been applied to workplace behavior (sitting reduction, safety compliance), environmental behavior (energy conservation, recycling), education, tourism, and organizational change. The underlying logic (diagnose the barrier, match the intervention type) applies to any target behavior.
Sources and Further Reading
- Michie, S., van Stralen, M. M., & West, R. (2011). The behaviour change wheel: A new method for characterising and designing behaviour change interventions. Implementation Science, 6, 42.
- Michie, S., Atkins, L., & West, R. (2014). The Behaviour Change Wheel: A Guide to Designing Interventions. Silverback Publishing.
- Michie, S., Johnston, M., Abraham, C., et al. (2005). Making psychological theory useful for implementing evidence based practice. Quality and Safety in Health Care, 14(1), 26-33.
- Cane, J., O’Connor, D., & Michie, S. (2012). Validation of the theoretical domains framework for use in behaviour change and implementation research. Implementation Science, 7, 37.
- Michie, S., Richardson, M., Johnston, M., et al. (2013). The behavior change technique taxonomy (v1) of 93 hierarchically clustered techniques. Annals of Behavioral Medicine, 46(1), 81-95.
- West, R., Michie, S., et al. (2020). Applying principles of behaviour change to reduce SARS-CoV-2 transmission. Nature Human Behaviour, 4, 451-459.
- Sherman, S. M., et al. (2021). COVID-19 vaccination intention in the UK: results from the COVID-19 vaccination acceptability study (CoVAccS). Human Vaccines & Immunotherapeutics, 17(6), 1612-1621.
- Fulton, E., et al. (2016). StopApp: Using the behaviour change wheel to develop an app to increase uptake and attendance at NHS Stop Smoking Services. Healthcare, 4(2), 31.
- Gould, G. S., et al. (2017). Designing an implementation intervention with the behaviour change wheel for health provider smoking cessation care for Australian Indigenous pregnant women. Implementation Science, 12, 114.
- Edwardson, C. L., et al. (2018). Effectiveness of the Stand More AT (SMArT) Work intervention. BMJ, 363, k3870.
- Steinmo, S., et al. (2015). Characterising an implementation intervention in terms of behaviour change techniques and theory. Implementation Science, 10, 111.
- Greene, C., & Wilson, P. (2022). A scoping review of infection prevention and control behaviour change interventions. Journal of Infection Prevention, 23(3), 108-117.
- Connell, L. E., et al. (2019). Can surveys of health professionals inform the development of behaviour change interventions? Implementation Science, 14, 2.
