Laws of PM Design Jakob's Law

Jakob's Law

Users Expect What They Know

Users spend most of their time on other products — so breaking the usual UI patterns costs you more than it earns.

Why PMs should care

Your users open your app for five minutes a day. They open Instagram, Gmail, WhatsApp, their banking app, their maps app, and Spotify for the other 95 minutes.

Every interaction pattern they've learned — hamburger menus in the top-left, pull-to-refresh on lists, bottom tab bars for main navigation, an X in the top-right of pop-ups, swiping left to delete on a list — came from those other products, not yours.

Being novel in common UI patterns costs you. It looks creative in a design review and confusing in a user test. Save the novelty for the moments where your product actually does something different from the competition. Use industry-standard patterns everywhere else. Most PMs under-invest in this because 'boring is good' isn't something that looks impressive on a CV.

Example in product work

A fintech team redesigns its navigation. The existing three-column tab bar at the bottom (Home / Portfolio / Discover) is replaced with a novel radial gesture menu that users activate by pressing and holding anywhere on the screen.

The design is genuinely beautiful, wins an internal award, and tests well with the 12 users who participated in the co-design workshop. It ships.

Within two weeks, app-store reviews mentioning 'can't find the buy button' triple. Retention drops 6%. The 5% of users who mastered the gesture love it and post about it on Twitter. The other 95% uninstall or fall back to doing everything from the home screen.

The novelty was internally expensive and externally worthless. Rolled back in 11 days.

What to do when you see it

Sources & further reading

Back to all 59 laws