10 MORE Rules for Better UX Design

Von Restorff Effect (Isolation effect)


Jon Haines

3 years ago | 4 min read

11.) Round Number Bias

The posted image is a bit dated, but still relevant, especially considering the rise of online dating. The graph from 2010 explains that men on OkCupid tended to round their heights up to an even six feet to give them a better shot at women looking for a taller man.

This is a tendency that we see all throughout society. Top ten lists, marathoners looking to run under four hours, and Alex Rodriguez’s failed quest to reach 700 home runs. We’re built to appreciate 5’s and 0’s psychologically.

The Round Number Bias is the human tendency to pay special attention to numbers that are round in some way. From a UX lens, understand that your users will take special note of lists that contain a round number of entries (notice the title of this list one more time).

12.) Von Restorff Effect (Isolation effect)

Look at the balloons in the corresponding image. Notice how the white balloons seem to blend into the background, and yet the red seems to jump right at you. Sure, this may be due to the more aggressive color of the single balloon, but Hedwig von Restorff would suggest there’s something more happening here.

The Von Restorff Effect states items that stand out from their peers are more memorable. This isn’t just for images alone, but other things. For example, in this list of words: desk, chair, bed, table, chipmunk, dresser, stool, couch, the word that stands out most is chipmunk, since it is the only animal in a sea of furniture.

13.) Law of Proximity

Our brains do funny things when we look at grouped imaged. The circles on pictured are placed in a certain way to make us think they’re grouped together. In fact, in the particular arrangement, we might even say there’s a triangle formed.

This is the Law of Proximity — yet another Gestault Principle that says objects that are near, or proximate to each other, tend to be grouped together. Remember this when designing aspects of a site or application that belong together.

14.) The Principle of Familiarity

When faced with new phone applications, the lack of screen space forces app designers to use icons as shortcuts to describe what things mean. A magnifying glass may represent either a zoom or a search and a silhouette of a person may represent your profile page. People want applications to look and feel like ones they’ve already spent time on.

This is the Principle of Familiarity, or the Mere-exposure Effect. For more, check out Jakob Nielsen’s Top 10 Mistakes in Web Design.

15.) The Law of Closure

Do you see two triangles in the corresponding image? You most likely do, but would you believe there’s just one?

The Law of Closure tells us that our brain loves to fill in gaps, including this instance which contains several uncompleted shapes that when placed all together form a second non-existent triangle. This is a law seen in logos like FedEx’s famous arrow. The concept gives brands a sort of minimalist feel.

16.) Anchoring Bias

Picture an auction house. An item is up for bid. The auction is assuming it will go for no more than $100. Unless it’s too unbelievable, when the first bid is placed at $300, it shifts the narrative to believe that $300 is actually the price from where to start.

The Anchoring Bias, or focalism, is where an individual depends too heavily on an initial piece of information offered (considered to be the “anchor”) when making decisions.

17.) The Rule of the First Impression

A first impression can make or break a job interview. It sets the tone for personal and professional relationships, similar to how the Anchoring Bias sets the tone in determining fair prices.

The Rule of First Impression states that people put a huge emphasis on the first experience that they have with a person or product. This is especially important for designers considering that it takes just 50 milliseconds for users to make judgements based on you work.

18.) The Law of Prägnanz (Law of simplicity)

The Olympic rings image is simple, yet represents the more complicated concept of interlocking continents. The rings in the corresponding images lack the color you would see for the Olympics, but carries the same concept.

Where the Law of Prägnanz comes in is in the fact that we see five circles interlocked instead of the many more ambiguous shapes that are formed by the circles. The Law of Prägnanz tells us that people perceive complex things as simplistic forms in order to recognize things more easily.

19.) Postel’s Law

Postel’s Law, also known as the Robustness principle, was made for software development. It states that you should be conservative in what you do, be liberal in what you accept from others.

For example, if you are creating programs that send messages to other machines (or to other programs on the same machine), these should conform completely to the specifications. However, programs that receive messages should accept non-conformant input as long as the meaning is clear.

20.) Peak-End Rule

To conclude this list, take a look at the corresponding image. Users end up looking back on their experiences of using products in a pretty specific way.

The Peak–End Rule states that users will judge an experience largely based on how they felt at its peak (i.e., its most intense point) and at its end, rather than based on the total sum or average of every moment of the experience.

Thank you for reading and don’t forget to read Part 1 of this series. Yo


Created by

Jon Haines







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