Behaviour (Fogg B=MAP)
Practice
How familiar is it?
What it is
Practice is the Ability lever of prior familiarity — actions we have done before are easier, even if objectively complex.
Why it works
Non-routine is one of Fogg''s six simplicity factors: actions that fit our existing routines are easy, and unfamiliar ones are hard regardless of their objective complexity. In interface terms this is Jakob''s Law, Jakob Nielsen''s observation that people spend most of their time on other sites, so they expect yours to work the way those do. Familiarity is effectively borrowed ability — a pattern the user already knows costs almost nothing to operate, because the learning was paid for elsewhere. The corollary is uncomfortable for designers: novelty at the interaction layer is a cost the user pays, and it is only worth charging when the new pattern is substantially better, not merely more distinctive. Visual identity can be original at very little cost; interaction grammar cannot.
How to apply it in design
Use UI patterns the target user already knows from products they use daily. Familiar gestures, layouts, and conventions reduce the learning load to near zero.
Where you'll see it
- Conventional placement for navigation, search, cart and account
- Gestures borrowed from the apps the audience already uses daily
- Standard form behaviour, including how errors and validation appear
- Icons used with their established meanings rather than reinvented ones
- Platform conventions respected on each platform rather than unified across them
Example
A meditation app using Spotify-style playlist UI lets users skip the entire learning curve — they already know how to operate it.
Failure mode
Inventing novel patterns for the sake of design distinctiveness creates ability debt the user has to pay. Originality at the interaction layer is usually a tax.
When not to use it
Convention is the wrong default when the established pattern is genuinely bad, or when the underlying task has no good precedent. Deviating is also justified when the existing convention encodes a business model you are rejecting — a product built to remove a step that competitors depend on has to look different in order to be different. And familiarity assumes you know which products your audience actually uses; borrowing patterns from software your users have never opened gives you all the cost of convention with none of the benefit.
The ethical line
Familiar patterns carry expectations, and violating them where it profits you is a recognised deceptive practice. A button styled as the platform''s standard confirm that actually adds a subscription, a checkbox pre-ticked against the convention for consent, or an X that opens rather than closes — these work precisely because the user is operating on autopilot, which is what convention invites. Using learned behaviour to produce an outcome the user did not intend is the definition of a dark pattern. Follow the convention or clearly break it; do not imitate it and then invert the result.
What to measure
Watch error rate and hesitation on first use — time-to-first-successful-action for new users is the clearest read on familiarity. If experienced users of comparable products struggle in your flow, the deviation is costing more than it returns.
Frequently asked questions
What is Jakob's Law?
Jakob's Law, from Jakob Nielsen, states that users spend most of their time on other sites and therefore expect yours to work in the same way. It is the interface expression of Fogg's non-routine simplicity factor: familiar patterns require almost no learning because the user paid for that learning elsewhere.
Should products use familiar UI patterns or be original?
Be original in visual identity and conservative in interaction grammar. Novel interaction patterns are a cost the user pays every time, so they only pay off when the new pattern is genuinely better rather than merely distinctive. Personality lives in voice, type and colour, not in relocating the cart icon.
How does familiarity affect conversion?
Directly, through error rate and hesitation. Users operating a familiar pattern act almost automatically, while an unfamiliar one forces conscious problem-solving at exactly the moment you want momentum. First-time success rate is usually the cleanest measure of the cost.
When is breaking convention justified?
When the standard pattern is genuinely poor, when no good precedent exists for the task, or when the convention encodes something you are deliberately rejecting. What is never justified is imitating a convention and inverting its outcome, which is the mechanism behind most dark patterns.
Related skills
Source: Growth.Design — B=MAP (Ability)
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