User experience and human–computer interaction.

Design principles:

  • Gestalt principles (Prägnanz)

  • Serial-position effect

  • Isolation effect

  • Fitts’s law: The time to move to a target depends on the size of the target and the distance to it.

  • Hick’s law: The time to make a decision increases with the number and complexity of choices.

  • Jakob’s law: People spend most of their time on other sites, so they prefer your site to work the same way as the other sites they already know.

  • Miller’s law: The average person can only keep 7 (plus or minus 2) items in their working memory.

  • Parkinson’s law: Any task will inflate until all of the available time is spent.

  • Law of conservation of complexity:1 For any system, there is a certain amount of complexity which cannot be reduced.

  1. Also known as Tesler’s Law.