UX design (user experience design) is based on several principles and laws that guide user experience design. These are often called the laws or principles of UX design, and they help designers create user-friendly, intuitive, and efficient user interfaces. Here are the key laws of UX design:

Hick’s Law

The more options the user has, the longer it takes to make a decision.

In practice, this means that the menus and choices in the user interface must be clear and limited, so that the user can make decisions quickly. Complexity and too many choices slow down the user and can cause frustration.

Fitts’s Law

The time it takes to reach a target depends on its size and distance.

The bigger and closer the object (e.g. button or link) is, the easier and faster it is to use. This law emphasizes the correct placement and adequate size of buttons and interaction elements so that they are easy and quick to use.

Jakob’s Law

Users expect a site or user interface to work in the same way as other sites they have used.

This means that users expect a certain level of consistency and familiarity. It is often more efficient to follow industry standards and familiar practices than to create completely new and unique solutions that can confuse the user.

Tesler’s Law of Conservation of Complexity

Every system has a certain amount of complexity that cannot be completely removed, but can be hidden from the user.

This means that complex functions should be hidden from the user or simplified so that the user interface looks easy and straightforward, even if there are complex processes in the background.

Miller’s Law

A person can keep about 7 (± 2) units of information in their working memory at a time.

The user interface and the amount of information should be limited so that the user is not presented with too much information at once. This makes the user interface easier to adopt and reduces the cognitive load.

Pareto principle (80/20 rule)

80% of the consequences are due to 20% of the causes.

This principle suggests that most of the user’s activity is focused on a small number of parts or features of the user interface. The designer should focus on optimizing these key elements that have the greatest impact on the user experience.

Doherty’s threshold effect

The user experience improves significantly when the system reacts to the user’s actions in less than 400 milliseconds.

This means that the responsiveness of the system is important, and the user needs to feel that their actions will immediately lead to some result.

Aesthetic-Usability Effect

Aesthetic and beautiful user interfaces are perceived as easier to use.

Users tend to believe that a visually pleasing user interface is also functionally better. Good aesthetics can therefore increase the user’s forgiveness towards small mistakes.

The Zeigarnik effect

People remember unfinished tasks better than completed ones.

This can be leveraged by using to-do lists, staged processes, or a step-by-step interface to help users keep track of their unfinished tasks.

Postel’s Law (Robustness Principle)

“Be permissive in what you accept, but precise in what you give.”

This law is particularly applicable to forms and the processing of data entered by the user: the system should be able to handle user input flexibly (e.g. several different formats), but ensure that the output data is clear and consistent.

Von Restorff effect (Isolation Effect)

When there is one unusual element among similar elements, it stands out and is better remembered.

Used to emphasize important elements, such as calls to action, to attract the user’s attention.

Law of Consistency

Consistency in the user interface improves usability and reduces errors.

When elements behave and look consistent across contexts, users can predict what will happen, making the interface more intuitive.

Keeping these principles in mind helps create efficient, intuitive and pleasant user experiences that improve user engagement and satisfaction.