Laws of UX

Khashayar Shomali

Khashayar Shomali

Senior UI/UX Product Designer.

Miller’s Law

The number of objects an average person can hold in working memory is about seven, also known as The Magical Number Seven, Plus or Minus Two.

Laws of UX: Miller's Law

Fitts’s Law

The longer the distance and the smaller the target’s size, the longer it takes.

Laws of UX: Fitt's Law

Jakob’s Law

Users spend most of their time on other sites. This means that users prefer your site to work the same way as all the other sites they already know.

Laws of UX: Jakob's Law

Law of Proximity

Things closer to each other appear more related than things farther apart.

Laws of UX: Law of Proximity

Parkinson’s Law

Work expands so as to fill the time available for its completion.” If something must be done in a year, it’ll be done in a year.

Laws of UX Parkinson’s Law

Von Restorff Effect

When multiple similar objects are present, the one that differs from the rest is most easy to remember.

Laws of UX: Von Restorff Effect

Zeigarnik Effect

Incomplete tasks are most likely to be remembered. You could help the users remember certain uncompleted tasks by adding a simple progress bar.

Laws of UX: Zeigarnik Effect

Hick’s Law

Time for decision making depends on how many and how complex the choices are.

Laws of UX: Hick's Law

Serial Position Effect

This effect states that the first and the last terms are most likely remembered.

Laws of UX: Serial Position Effect

Law of Common Region

The law of common region expresses that elements are grouped together when they share an area with a clear boundary between them.

Laws of UX: Law of Common Region

Goal-Gradient Effect

As people get closer to a reward, they speed up their behavior to get to their goal faster.

Laws of UX: Goal-Gradient Effect

Law of Pragnanz

When you’re presented with a set of ambiguous or complex objects, your brain will make them appear as simple as possible.

Laws of UX: Law of Pragnanz

Tesler’s Law

Tesler argues that an engineer should spend extra time reducing complexity on the application instead of making users spend more time on the task they’re trying to perform.

Laws of UX: Tesler's Law

Peak-End Rule

if the peak and the end are good, people will conclude that the entire experience was good.

Laws of UX: Peak-End Rule

Aesthetic-Usability Effect

People tend to believe that things that look better will work better even if they aren’t actually more effective or effecient.

Laws of UX: Aesthetic-Usability Effect

Doherty Threshold

If a response appears after the 400 ms threshold, users eventually become disinterested according to a study done in the late 1970s.

Laws of UX: Doherty Threshold

Law of Similarity

The human eye tends to perceive similar elements in a design as a complete picture, shape, or group, even if those elements are separated.

Laws of UX: Law of Similarity

Pareto Principle

For many events, roughly 80% od the effects come from 20% of the causes.

Laws of UX: Pareto Principle

Postel’s Law

Be conservative in what you do, be liberal in what you accept from others. The more you plan the more resilient the design will be.

Laws of UX: Postel's Law

Occam’s Razor

Simplicity is better than complexity.

Laws of UX: Occam's Razor