Jacob's Law
Users spend most of their time on other sites. This means that users prefer your site to work the same way as all the other sites they already know.
When to Use
Follow established patterns
Use familiar interaction patterns, navigation structures, and conventions that users already know from other sites.
Leverage existing mental models
Design interfaces that align with users' existing expectations based on their experience with other products.
Reduce learning curve
By following conventions, you reduce the time users need to learn how to use your interface.
When to Avoid
Don't break conventions unnecessarily
While innovation is valuable, avoid breaking established patterns unless you have a compelling reason and can provide clear guidance.
Origin
Jacob's Law is named after usability expert Jakob Nielsen, who observed that users prefer interfaces that work like the ones they already know. Since users spend most of their time on other websites and applications, they develop expectations about how interfaces should work. Meeting these expectations reduces cognitive load and improves usability.