>[!abstract] >In user interface design and software design, the principle of least astonishment (POLA), also known as principle of least surprise, proposes that a component of a system should behave in a way that most users will expect it to behave, and therefore not astonish or surprise users. The following is a corollary of the principle: "If a necessary feature has a high astonishment factor, it may be necessary to redesign the feature" (Wikipedia, 2025). >[!related] >- **North** (upstream): [[Usability engineering]] >- **West** (similar): [[KISS principle]], [[Law of least effort]] (people naturally choose paths requiring the least cognitive/physical effort, so design should align with that) >- **East** (different): [[Principle of maximum surprise]] (interfaces or designs that deliberately violate user expectations, sometimes in art or gamification) >- **South** (downstream): [[User interface conventions]] (e.g., standard keybindings, menu placements, error messages behaving consistently across systems)