Hick's Law: Designing Long Menu Lists
Hick's Law (or the Hick–Hyman Law) says that the more choices you present to your users, the longer it takes them to reach a decision. However, combining Hick's Law with other design techniques can make long menus easy to use. (3 min. video)
The Availability Heuristic
People make decisions based on the information that is most readily available to them. Understanding how the availability heuristic works will help you design for the way people think. (2 min. video)