Behavioural design starts with something a person is trying to do and examines what makes that action more or less likely. The product may offer the necessary feature while the surrounding experience makes using it inconvenient, confusing, or poorly timed.

A reminder to submit expenses, for example, is unlikely to solve a problem caused by missing receipts or an approval process nobody understands. The design question extends beyond making the reminder more persuasive.

Define the behaviour and its circumstances

Specify who should be able to do what, when, and for what purpose. “Improve engagement” leaves too much undefined. “Help employees submit a complete expense claim before the monthly deadline” gives research a concrete experience to investigate.

The Fogg Behavior Model brings motivation, ability, and a prompt together as a way to examine behaviour. Such a framework can organise questions, but it does not replace evidence about the particular audience or establish that a proposed intervention will work.

Use contextual inquiry or interviews about recent events to understand constraints. In the illustrative expense example, people might delay because receipts arrive through several channels. A better collection process could matter more than the wording of a notification.

Test the proposed explanation

Write down how the change is expected to help. A reminder timed after travel, a clearer explanation of required documents, and a default category each address different possibilities. Testing them as an undifferentiated redesign makes it harder to understand which mechanism mattered, although evaluating the complete experience may still be the practical objective.

An A/B test can assess a suitable measurable comparison when its design and sample support the question. Qualitative research can reveal misunderstanding, pressure, or workarounds that a completion metric misses.

Look beyond the immediate action. More submitted claims may include more errors, additional reviewer work, or claims made before people have checked them. Define accompanying measures that reflect these consequences.

Preserve an informed choice

Defaults, reminders, and friction affect whose interests the design serves. Making a beneficial action easier can be valuable; making an unwanted subscription hard to cancel creates a different relationship with the user.

Explain material consequences, make alternatives discoverable, and allow reversal where appropriate. Evaluate the experience with the people affected, including those for whom the preferred path is unsuitable. Good behavioural design can explain both the behaviour it aims to support and why supporting it is worthwhile for the person taking the action.