No. 21 Tesler’s Law

Complexity never disappears. Someone handles it.

Every task has some complexity that can’t be removed. It only moves.

If the app doesn’t handle it, the user has to. Make the app do the work.

Find one thing users type. Let the app do it.

In the 1980s, Larry Tesler argued every app has complexity that can’t be removed. Only moved.

His math: better an engineer spends an extra week than a million users each lose a minute a day.

It’s also called the law of conservation of complexity.

• Dan Saffer, Designing for Interaction, 2nd ed. (2010), interview with Larry Tesler
• Laws of UX, “Tesler’s Law” (lawsofux.com)

Save this for the next time someone says “users can just type it in.”