Complexity that will not vanish
Larry Tesler, who pioneered cut and paste, argued every application has irreducible complexity (Saffer, 2009); the question is who handles it. An engineer spending an extra day could save millions of users a minute each. Tesler (2012) recounts removing modes so users need not remember state. Complexity left with users becomes cognitive load (Sweller, 1988).
Moving complexity into the system
Smart defaults are the commonest route: pre-fill what most people would choose. Inferring country from location, card type from number and address from postcode work the same way and greatly improve mobile form usability. Piling options onto settings pushes complexity to users and, as Iyengar and Lepper (2000) showed, can cause choice overload.
The oversimplification trap
Norman (2010) says confusion, not complexity, is the enemy. Hiding features experts need forces workarounds, and Maeda's (2006) simplicity includes organising, not just removing. Balance a simple default path for novices with advanced features via progressive disclosure; Yablonski (2020) frames it as distributing complexity wisely.
FAQ
- Is Tesler's law the same as simplification?
- No; complexity does not disappear, so move it from users to the system.
- What is the easiest way to apply it?
- Good defaults and autofill that pre-supply what most people would choose.
Sources reviewed: 2026-10-27
References
- Saffer, D. (2009). Designing for interaction: Creating innovative applications and devices (2nd ed.). New Riders. Includes Larry Tesler's own explanation of the law of conservation of complexity.
- Tesler, L. (2012). A personal history of modeless text editing and cut/copy-paste. Interactions, 19(4), 70–75. Tesler's memoir of modeless editing and cut/copy-paste.
- Norman, D. A. (2010). Living with complexity. MIT Press. Argues confusion, not complexity, is the enemy.
- Maeda, J. (2006). The laws of simplicity. MIT Press. Ten laws of simplicity such as reduce and organise.
- Yablonski, J. (2020). Laws of UX: Using psychology to design better products & services. O'Reilly Media. Applies Tesler's law to modern product examples.
- Sweller, J. (1988). Cognitive load during problem solving: Effects on learning. Cognitive Science, 12(2), 257–285. The origin of cognitive load theory, explaining why leftover complexity burdens users.
- Iyengar, S. S., & Lepper, M. R. (2000). When choice is demotivating: Can one desire too much of a good thing? Journal of Personality and Social Psychology, 79(6), 995–1006. Shows too many options can demotivate choice.