Designing for habit formation

The Hook Model, developed by Nir Eyal, provides a framework for building habit-forming products through four key stages that create features users naturally integrate into their routines.

• Trigger prompts user action through external means like notifications and app icons, or internal motivators like emotions and desires.
• Action is the simplest behavior done expecting a reward. This step should be effortless and immediate, like pulling to refresh a feed or tapping a like button. The simpler the action, the more likely users are to perform it.
• Variable reward keeps users engaged by varying the timing or content of rewards.
• Investment involves users contributing to improve their future experience. When users invest time or effort, like creating Pinterest boards, they're more likely to return.^[1]