Design Laws

Understand the role psychology plays when designing user interfaces, and discover ways to apply these findings to your own designs.

Hick's Law

Hick’s Law states that the more options a user is presented with, the longer it will take them to make a decision.

Hick's Law

Man looking at vending machine with many options.

Fitts's Law

Fitts's Law states that the amount of time taken to move to and select a target is a function of the distance to and size of the target.

Fitts's Law

A man aiming a bow and arrow at a far away target.

Tesler's Law

Also known as "The Law of Conservation of Complexity", Tesler's Law states that systems have an inherent amount of complexity that cannot be reduced.

Tesler's Law

A set of busy, winding motorway roads looping and crossing each other.

Jakob's Law

Jakob's Law states that users spend more time on other websites so they expect your website to work in the same way, that they are already familiar with.

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A floppy disk.

Von Restorff Effect

Also known as "The Isolation Effect", the Von Restorff Effect states that users are more likely to remember an object if it is visually different from similar objects.

Von Restorff Effect

A single yellow pepper surrounded by red peppers.

Miller's Law

Miller's Law states that the average person can only keep 7 (plus or minus 2) items of information in their working memory at a time.

Miller's Law

Seven different cans of fizzy drink.

Aesthetic-Usability Effect

The Aesthetic-Usability Effect states that users often perceive visually-pleasing products as being easier to use.

Aesthetic-Usability Effect

iPad being held above a desk.

Pareto Principle

The Pareto Principle (or the 80/20 rule) states that ~80% of effects come from ~20% of the causes.

Pareto Principle

Crops on farm land with mountains in the background.

Doherty Threshold

If a computer responds to a users input in less than 400ms, the user will take less time to make their next decision.

Doherty Threshold

Athlete waiting to start sprinting at a start line.