What is cognitive load
When we, for example, visit a site, there are many things for our brain to learn to navigate and complete tasks. For instance, where buttons, text, and images are located. Also, what kind of information is presented and how much is relevant. These are all things we need to learn and keep in our brains’ working memory. The effort takes to learn all of these things is cognitive load.
Why it should be minimised
We usually have a mission when we visit a site, and it’s usually to complete a task. By minimizing cognitive load, we make it easier to complete tasks. To remove cognitive load in user interface design is probably not possible. Even just a black screen with one button will generate some cognitive load.
Useful design principles
I use a few design principles as a checklist for minimizing cognitive load. It’s not a one-stop solution, but they are a good start.
Remove visual obstacles that slow the user down. Things that don’t help the user complete a task should probably be left out. Avoid having several things calling for attention simultaneously, like images, buttons, and modals. And does the chatbot really need to be sticky in the right corner?
Re-use existing patterns
Use well-established patterns for information hierarchy and navigation. Don’t re-invent patterns. Assume the user knows the most common ones and design around them. Unexpected navigation patterns lead to confusion.
Guide the user
Lead the user with clear visual cues. On a landing page, use one primary CTA, for example, “Signup” and one secondary CTA, for instance, “Login”. Use contextual onboarding to highlight new features. A good example is the one for Chromecast. Few users read onboarding slides.
Aim for text to be easy to read instead of pretty. The Internet is full of easy-to-read fonts. Pick one of them instead of one that looks visually aesthetic. Bump up the font size and use a type system like Materials Designs to make it scale quickly. Avoid text on images. Even if you use a gradient, it’s unnecessary and probably hard to read.
Give the user the bare minimum of choices to complete a task. When a user gets too many options, the cognitive load goes up, and the brain slows down to handle all of the information. The user gets frustrated not being able to complete the task. So keep choices down and make the ones available relevant to complete a task.
These principles have helped me when designing. I hope you find them helpful too.