Gestalt Principles and the Laws of UX: Part 4 - The Law of Closure

The scientific principles I use every day designing in tools like Figma were predominantly researched and documented between 1912 and 1960 - before the invention of computers and mobile phones or the gurus of UX at NNG.

Each week I am going to release a new Law of UX. This week is the first of the Gestalt Principles - The Law of Closure.

Don't want to wait? You can read my take on 9 Laws of UX in the full post on my website.

Our visual perception unconsciously completes incomplete objects.

Our brains are adept at interpreting incomplete visuals as complete ones, a principle that's invaluable in UX design.

Take the example of a progress bar in a form: it may not be fully filled, but as you advance through the steps, your brain instinctively 'completes' the image. This ability allows you to effortlessly track your progress, ensuring you remain informed and engaged throughout the process. This clever use of visual cues simplifies complex information, enhancing user understanding and interaction.

The power of closure in modern interfaces extends far beyond simple progress bars. Think about how mobile apps handle image carousels - showing just a slice of the next image at the screen's edge. Your brain automatically registers that there's more content to explore, without the need for explicit "swipe for more" instructions. I've found this subtle approach particularly effective in e-commerce designs, where it naturally encourages users to browse through product collections without feeling overwhelmed by too many options at once.

When designing navigation menus, the principle becomes even more fascinating. Take the ubiquitous hamburger menu icon - three simple lines that our brains instantly recognise as a button that reveals more options. This is closure at its most elegant - using minimal visual elements to convey maximum meaning. The same principle applies to those loading animations where dots appear and disappear in sequence - your mind automatically completes the circular pattern, creating a sense of continuous motion from just a few strategic visual elements.

The versatility of this principle becomes is on show above - take the 'stairs' icon, where a few diagonal lines efficiently convey elevation and progression. What I find particularly clever is how the 'cake' icon uses horizontal lines with a single dot on top - our brain doesn't need the full outline of a cake to understand what it represents; the subtle suggestion of layers topped with a cherry is enough. These icons demonstrate how understanding closure allows us to create intuitive, space-efficient designs that communicate clearly without overwhelming the interface.

The Law of Closure takeaways

1. Our brains automatically complete incomplete shapes and patterns to form whole objects
2. Simple, incomplete forms can be more effective than detailed illustrations in interface design
3. Strategic use of gaps and spacing can create meaningful icons while reducing visual complexity
4. When objects are incomplete but recognisable, users process information more efficiently

Further reading:

• The Laws of UX website: lawsofux.com
• Steve Krug’s Don’t Make Me Think
• Interaction Design Foundation IxDF: The Gestalt Principles
• My personal take on 9 Laws of UX

References:

• Home | Laws of UX
• Gestalt psychology