A system's behaviour should be consistent and predictable to the user.
The Principle of Least Astonishment (POLA) in UX design emphasises that the behaviour and appearance of a user interface should not surprise or confuse users.
It means that when people interact with a system, they should find it intuitive and in line with their expectations.
Avoiding unexpected or unconventional design choices helps users feel comfortable and confident when using a product, ultimately enhancing their overall experience.