The big picture
Fogg Behavior Model (B=MAP)
A behavior happens when motivation, ability, and a prompt meet at the same moment.
Practitioner frameworkA thinking tool for design. Direct tests of its effect are limited.
Example
Even during a sale, a long checkout line makes people walk away. Wanting something is not enough when the action is too hard.
Why it works
Strong motivation carries people through hard actions, and easy actions need little motivation. When the combination is above the action line and a prompt arrives, the behavior happens. Below the line, prompting does nothing.
On the web
When conversion is low, check effort and prompt placement before trying to raise motivation. Fewer fields and a CTA placed right after the decision make action easier without changing motivation.
When it backfires
Stacking notifications and discounts on people below the line only feels noisy. Reduce effort before adding more prompts.
Sources
Explains behavior with motivation, ability, and a trigger. Fogg later renamed the trigger a prompt in the 2019 book Tiny Habits.
Fogg, B. J. (2009). A behavior model for persuasive design. Persuasive 2009, Article 40. Open source
Publishes the B=MAP diagram and three kinds of prompts: sparks, facilitators, and signals.
Behavior Design Lab, Stanford University. Fogg Behavior Model. Open source
Connect with the classics
These links are editorial readings, not research findings. Check the original meaning on each classics page.
千里之行，始於足下。A journey of a thousand li begins beneath your feet. It matches the design move of shrinking the first action before trying to raise motivation.
Laozi · Dao De Jing Beginnings and completion →