Nudges and Persuasive Technology
Kosh's sign-up screen has to show the savings options in some order, with something already selected or nothing selected. There is no neutral way to lay it out: every version makes some choice a little more likely. The only question is whether you arrange it on purpose, and for whom.
The rule
A nudge steers the choice but keeps every option open and cheap to refuse.
Choice architecture is the way options are presented: their order, what is pre-selected, what is visible, how they are described. Economist Richard Thaler and legal scholar Cass Sunstein popularised the idea that because some arrangement is unavoidable, it may as well help people.
A nudge is a change to choice architecture that shifts behavior predictably without forbidding any option and without meaningfully changing the costs or rewards. A canteen that puts fruit at eye level nudges. A canteen that bans sweets, or taxes them heavily, does not — that is a rule or an incentive.
The opposite of a good nudge is sludge: friction that makes it harder to do what is in your own interest, such as a subscription you can join in one tap but can only cancel by phone.
Persuasive technology is BJ Fogg's term for computing systems designed to change what people believe or do. His definition excludes coercion and deception: persuasion changes minds or habits by honest means, not force or trickery.
Everything in this section — fast and slow thinking, B = MAP, the CREATE funnel — is powerful. That is why the nudge test matters.
The shortcut
Run every design through three questions. Are all options still available? Is saying no easy and cheap? Would the user thank you if they saw exactly how it works? Three yeses: a nudge. Any no: a rule, a bribe, or a dark pattern.
The proposal
On sign-up, "Save 10% of each salary" is pre-selected, based on what users who planned carefully chose.
Drills
Answer fast — trust the rule.
Which of these is a nudge?
What is choice architecture?
Kosh makes users call support three times to turn off auto-save. What is this?
Fogg's definition of persuasive technology excludes which methods?
A designer says, "I'll list the options in a neutral order so I'm not influencing anyone." What is the flaw?
Remember
- A nudge steers the choice but keeps every option open and cheap to refuse.
- Shortcut: options open, easy to refuse, and would users thank you? Three yeses.
- Trap: sludge and dark patterns that serve the business against the user.