The SUE | 4C Tool Explained: From Attention to Behaviour Routine
Most behavioural interventions are really half-interventions. They are designed for the first step: standing out, grabbing attention, getting someone to click, buy, sign up, or register. And then?
Then the design stops.
The assumption is that once you have set someone in motion, the rest happens naturally. But behaviour that happens once is not behaviour change. It is an incident. Behaviour change is when it repeats, when it becomes automatic, when it becomes part of someone's routine. That requires design across all four phases of the journey — not just the first.
The SUE | 4C Tool is a design framework that structures behavioural interventions in four sequential phases: Catch (gaining attention), Convert (turning attention into behaviour), Confirm (reinforcing the behaviour) and Continue (building a behaviour routine). The tool helps you design a complete behavioural journey — from the first point of contact to the habit you want to establish. More about the SUE Method →
Why half-interventions always fail
Imagine a health app wanting to encourage people to exercise daily. They launch a campaign, invest in a polished onboarding experience, offer a free trial. The downloads are impressive. But after six weeks, only 8% of users are still active.
Recognise the pattern? It is not unusual. It is the norm. The campaign was perfectly designed for the Catch phase: standing out, sparking curiosity, triggering the first download. But there was no design for the phase that determines whether someone stays — the confirmation that they made the right choice, the building of a routine that makes the behaviour automatic.
The problem is not the campaign. The problem is that the campaign was the only thing that was designed.
Behaviour does not work like that. A person doing something for the first time is at the beginning of a psychological journey. They gain attention, turn that attention into action, experience that action, and then decide — consciously or not — whether to do it again. If that journey is not designed, it does not unfold well by default. It loses people at precisely the moment they were almost won.
What is the SUE | 4C Tool?
The SUE | 4C Tool is the third step of the SUE Behavioural Design Method. After the SUE Influence Framework (step 1, which maps what drives people and what holds them back) and the SWAC tool (step 2, which diagnoses which type of intervention will move the behaviour), the 4C Tool structures the complete behavioural journey you want to design.
The four phases are:
- Catch — gaining attention: interrupting someone's existing pattern and creating relevance for the desired behaviour
- Convert — turning attention into behaviour: removing friction and making the desired behaviour the easiest choice
- Confirm — reinforcing the behaviour: validating the choice, removing doubt, making someone feel good about their decision so they are willing to repeat it
- Continue — building a behaviour routine: repeating the behaviour until it becomes automatic, by embedding routines that make willpower unnecessary
The power of the 4C Tool lies in the sequence. The phases are not arbitrary. They follow the psychological logic of how people make decisions, experience behaviour, and form habits. You cannot swap them. And you cannot skip any of them without breaking the journey at the exact point where you need it most.
Behaviour that happens once is not behaviour change. It is an incident. The 4C Tool designs the full journey.
Catch: attention is the beginning, not the goal
Catch is the phase most designers already know, and also the phase they most often overestimate. Gaining attention is necessary, but it is only the start of the journey. Attention that leads nowhere is budget wasted.
Effective Catch works on two levels simultaneously. First, it interrupts an existing pattern: it breaks the autopilot on which people move through their day. Second, it immediately creates relevance: it makes clear why this matters for the person, right now.
The System 1 principle applies in full force here. People process most information automatically, quickly, and without conscious attention. Gaining attention means activating the automatic system: visual salience, emotional relevance, surprise, personal recognition. Abstract claims about product quality or organisational values do not do this. Concrete, sensory, recognisable stimuli do.
An effective Catch connects to the pains and anxieties that the Influence Framework has mapped. When you know what genuinely preoccupies someone, you can design a Catch that resonates immediately — not as an interruption that irritates, but as a recognition that makes them think: "this is about me."
You've read about it. But what if you could apply it yourself — to customers, colleagues, citizens, or stakeholders?
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Convert: the barrier to first behaviour
Attention is not the same as willingness, and willingness is not the same as behaviour. Between the moment someone notices that something is relevant to them and the moment they actually act, there is a gap. The Convert phase is designed to bridge that gap.
Here the CAN principle from the SWAC tool applies in full force. Most designers think the Convert phase is about persuasion: giving the best arguments, formulating the strongest proposition, making the value as clear as possible. But the real bottleneck is almost never that people are not convinced. The bottleneck is that the behaviour is too difficult.
Difficult can mean many things. Cognitively difficult: too many steps, too many choices, too much thinking required. Socially difficult: it feels awkward, risky, or requires saying or doing something that deviates from what your environment does. Practically difficult: it costs time, money, or effort that is not currently available. Each of these makes the desired behaviour less likely, regardless of how strong the motivation is.
Convert design means removing friction to the minimum required for the desired behaviour. Not simplifying the behaviour until it means nothing, but designing the path of least resistance towards the desired action. Those who do this best have understood it most clearly: Amazon's one-click checkout, Spotify's autoplay, bank transfers that repeat by default. None of these systems persuade you of anything. They remove obstacles.
A Convert intervention succeeds when someone acts before they have had the chance to doubt. That sounds manipulative, but it is the opposite: it makes it easier for people who already want to do something to do what they were already planning to do.
Confirm: validating the choice before doubt sets in
Someone has performed the behaviour. They have clicked, registered, purchased, taken the first step. Now begins one of the most underestimated moments in the entire behavioural journey: the seconds, minutes, and hours immediately afterwards.
Behavioural economists call this post-decision dissonance: the doubt that arises after a decision, particularly when that decision required effort or commitment. People wonder whether they made the right choice. They look for confirmation. And when that confirmation does not come, the doubt grows, the sense of regret increases, and the likelihood of repeating the behaviour falls.
Most organisations leave this moment undesigned. After a purchase comes a confirmation email. After registration, a welcome message. But welcome messages about what the organisation offers confirm nothing. Confirmation is what the person feels about their own choice.
Effective Confirm interventions do two things. They explicitly validate the person's choice: you made the right decision, here is why. And they give the person an early win: a small, immediate success that shows them the choice is working. That success does not need to be large. It needs to arrive early.
An example: an insurance company wanting customers to store their policy documents digitally can send a message immediately after the download: "You've just secured your policy documents. That saves you an average of 47 minutes if you ever need them." That is Confirm. Not "thanks for using our app." But: your choice was smart, and here is the proof.
Continue: the habit that makes willpower unnecessary
Continue is the phase that makes the difference between an incident and a habit. It is also the phase most often absent from behavioural interventions, simply because organisations consider their work done the moment the first behaviour occurs.
But the first behaviour is the beginning, not the end. Habit formation takes an average of 66 days, with a range from 18 to 254 days, depending on the complexity of the behaviour and the consistency with which it is triggered. During that period, the behaviour is fragile. It depends on environmental cues, consistent triggers, a structure that keeps the behaviour running automatically when willingness fluctuates.
Continue design is design for the automatic. The goal is not to re-motivate someone repeatedly, but to embed the behaviour so thoroughly in the environment and the routine that it happens without a conscious decision being required. That is the definition of a habit: behaviour that occurs without deliberation.
In practice this means: building trigger structures that cue the behaviour at fixed moments (the SPARK from the SWAC tool), adapting the environment so that the desired behaviour becomes the default, and deploying social mechanisms that reinforce the new identity. Someone who begins to see themselves as a person-who-exercises needs less willpower to decide to go. The identity does part of the work.
A Continue intervention that works well eventually makes itself redundant. The habit has formed. The scaffolding can come down. The behaviour continues.
How the four phases work together
The 4C Tool is not a checklist. It is an architecture. Each phase builds on the previous one, and a weak link in the chain breaks the entire behavioural journey.
A beautiful Catch that leads to a Convert phase full of friction loses people at the hardest moment. A perfect Convert that results in first behaviour but has no Confirm moment leaves people in doubt. A good Confirm that does not lead to a Continue structure produces one-off behaviours that do not stick.
Imagine a municipality wanting more residents to separate their food waste. The Catch is a campaign that resonates emotionally: "Your kitchen is where new food production begins." The Convert is a free waste bin delivered to the home, with a fridge magnet showing what goes in and what does not. The Confirm is a letter two weeks later: "Your neighbourhood is separating 34% more food waste than last year. You are part of that." The Continue is a reminder every Thursday — the day before the collection round — via a push notification or a sticker on the bin.
Each phase designs a different moment in the journey. Together they make the behaviour not just possible, but likely, repeatable, and ultimately automatic.
This is exactly what the 4C Tool structures. Not the campaign. Not the proposition. The full journey, from the first moment of attention to the habit that makes willpower unnecessary.
How to use the 4C Tool in practice
You use the 4C Tool after completing the Influence Framework and the SWAC analysis. At that point you know your audience, what drives them and what holds them back, and which type of intervention is needed. The 4C Tool then helps you design the complete behavioural journey.
First step: Catch. Which touchpoints have the potential to break through the autopilot and immediately create relevance? Which pain or anxiety from your Influence Framework analysis can you address to generate immediate recognition? This is the moment to make the message as concrete and sensory as possible.
Second step: Convert. What friction currently exists between the attention and the first desired behaviour? Which steps can you remove, simplify, or automate? What is the smallest possible first action you can ask for that is still meaningful? Here the rule is: fewer steps is always better than more.
Third step: Confirm. What is the first thing someone sees, hears, or feels immediately after the first behaviour? Does that moment confirm the choice, or does it leave people in doubt? What is the first small win you can give, as early as possible in the experience? Every second of delay in Confirm costs you Continues.
Fourth step: Continue. Which triggers keep the behaviour alive in the moments when willingness is low? How do you embed the behaviour in the existing routine, so that it no longer requires a separate decision? Which social or identity mechanisms reinforce the new behaviour as a character trait rather than a task?
Your intervention portfolio must address all four phases. Most budgets go to Catch. Most behaviour change happens in Convert, Confirm, and Continue.
The SUE | 4C Tool is step 3 of the SUE Method
The Influence Framework (step 1) maps what drives people and what holds them back. The SWAC tool (step 2) translates those insights into the right type of intervention. The SUE | 4C Tool (step 3) then structures the complete behavioural journey — from attention to routine.
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Frequently asked questions
What is the SUE | 4C Tool?
The SUE | 4C Tool is a design framework that structures behavioural interventions in four sequential phases: Catch (gaining attention), Convert (turning attention into behaviour), Confirm (reinforcing the behaviour) and Continue (building a behaviour routine). The tool helps you design a complete behavioural journey — from the first point of contact to the habit you want to establish.
What is the difference between the 4C Tool and the SWAC tool?
The SWAC tool diagnoses which type of intervention you need: Spark, Want, Again or Can. The 4C Tool structures the full journey of your target audience, from first attention to routine. SWAC answers "what kind of intervention do I build?". The 4C Tool answers "what does the full behavioural journey look like?". Together they form the final step of the SUE Method.
Why does behaviour change fail after the first step?
Because most interventions are designed for the Catch phase only: standing out, grabbing attention, triggering the first behaviour. But behaviour that happens once is not behaviour change. Without a Confirm mechanism, people doubt their first step. Without a Continue design, the behaviour fades once the external prompt is removed. The 4C Tool forces you to design all four phases, not just the first.
How do you use the 4C Tool in practice?
You use the 4C Tool after the SUE Influence Framework (step 1) and the SWAC analysis (step 2). At that point you know your audience, what drives them and what holds them back, and which type of intervention is needed. The 4C Tool then helps you design the full behavioural journey: which touchpoints attract attention (Catch), which remove the barrier to first behaviour (Convert), which confirm the choice (Confirm), and which build the routine (Continue).
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