Laws of UX

The “laws of UX” refer to a collection of time-tested principles derived from psychology, human-computer interaction, and cognitive science that guide how users perceive, process, and interact with interfaces. While not codified as an official legal framework, these “laws” or principles serve as mental models and rules of thumb to help designers create more intuitive, user-centered experiences

What is Jakob’s Law?

Users expect your site or product to behave similarly to other products they already use.

What is the implication of Jakob’s Law?

Familiar design patterns reduce cognitive load and help new users learn your interface more quickly.

What does Fitts’s Law state?

The time required to move a pointer to a target is a function of the target’s distance and size.

What is the implication of Fitts’s Law?

Larger and closer targets are easier and faster to click or tap.

What does Hick’s Law indicate?

The time it takes to make a decision increases with the number and complexity of choices.

How can you apply Hick’s Law in design?

Reducing options and simplifying the decision-making helps users make quicker, confident choices.

What is the essence of Miller’s Law?

The average person’s working memory can hold about 7 ± 2 items at once.

What should you do according to Miller’s Law?

Break complex information into manageable chunks to prevent cognitive overload.

What is Tesler’s Law about?

Every application has inherent complexity that cannot be removed, only shifted.

What implication does Tesler’s Law have for designers?

Designers can simplify the user interface but must manage some complexity by the system or user.

Define the Aesthetic-Usability Effect.

Users perceive more aesthetically pleasing designs as easier to use.

What is the implication of the Aesthetic-Usability Effect?

Good visual design improves perceived usability and user trust.

What does the Peak-End Rule state?

People judge an experience mainly by how they felt at its peak and at its end.

How can you optimize user experience based on the Peak-End Rule?

Ensure the most memorable moments and conclusion are positive.

What is the Von Restorff Effect?

When multiple similar stimuli are presented, the one that differs is more likely to be remembered.

How can you apply the Von Restorff Effect in design?

Emphasize important elements visually to guide user attention.

Define the Doherty Threshold.

Productivity improves when system response times are less than 400 milliseconds.

What is the implication of the Doherty Threshold?

Users feel more engaged when interaction feedback is nearly instantaneous.

What is the Pareto Principle (80/20 Rule)?

Roughly 80% of outcomes come from 20% of causes.

How should designers use the Pareto Principle?

Identify and optimize the 20% of features that users value most.

What is Occam’s Razor?

The simplest solution among competing designs is usually the best.

What should you avoid according to Occam’s Razor?

Avoid unnecessary complexity in designs.

Define the Zeigarnik Effect.

People remember uncompleted or interrupted tasks better than completed ones.

How can the Zeigarnik Effect be utilized in design?

Provide clear progress markers for incomplete tasks to motivate users to return.