UX Design: The Law of Similarity

When designing websites, there is more to consider than meets the eye. A whole range of psychological laws come into play when it comes to the UX design of websites.

This article is about the Law of Similarity and is the first article in a 5-part series on UX design principles.

Gestalt psychology is a branch of psychology that deals with human perception and describes the ability to recognize structures and organizing principles in sensory impressions. It's not just about websites, as these laws can be applied to all kinds of things, whether it's cars, real estate, apps or websites.

The law of similarity states that we perceive similar elements as belonging together. It doesn't matter which properties this similarity refers to. Color, shape, size, movement and orientation can signal that it is the same “group” of objects and that they probably have a common meaning or function. The more similarities two elements have, the stronger our feeling is to group these elements.

Example: In the image below we automatically see 4 vertical rows (and not 3 horizontal rows). In this example, the similarity came from the shape.

This effect of togetherness can also be used for web design or UX design to enable intuitive navigation.

For example, a certain button can always appear in the same style, shape and color across the entire website. This makes the function of a button intuitively clear to every user of the website, regardless of whether the user is on a subpage or on the homepage.

Likewise, the application of the similarity principle gives the entire website a consistent design or a uniform design of various elements and helps the user to navigate better through the website.

‍