Design Psychologies 101: use the way humans think to make better UI

In my previous medium post, I wrote that the purpose of Interface Design is to ease up an understanding of information.

Psychology explores the way humans perceive the world around them. So it helps to build more intuitive and human-fit interfaces and experiences.

To some extent, we may say that the world is one BIG natural interface that affects the way our brain expects artificial UI to work.

UI designers should adopt these principles at work.

Principle 1: Hick’s law, Cognitive Load and Information Understanding

Hick’s Law tells that Time to make a decision increases with the complexity of available options.

For UI designer this means The more complex UI we build, the more time it takes for a user to process it.

Today we observe some shift that happens to UI: the rise of Voice UI, which is a good illustration of UI simplicity. We can make purchases, make phone calls, set appointments with our voice instead of mobile and desktop UI.

Here we come to the idea of the cognitive load caused by Hick’s Law. Remembering the UI pattern of Voice Interface requires less cognitive load comparing to Graphic Interface because it resembles the talk UI pattern we all know.

Designer tips you can apply to your UI:

• Break your UX in smaller steps to less cognitive load
• Present new concepts eventually and consistently, don’t present features that are described by other features, without presenting the later first.

Principle 2: Miller’s law and limits of human short-term memory

Miller’s law says that the average human can memorize around 7 items in short-term memory.

It doesn’t mean you should always limit your interfaces to 7 items, it means that users perceive information in chunks around 7 items each.

What does it mean for the interface?

Group your interface to logical chunks to make the scanning of content more effective.

Here’s how it can be applied to the way you organize text:

Bad example:

Bad Headline. Bad Paragraph with -bad bullet.-bad bullet,-bad bullet,-bad bullet.

Good example:

Good Headline

Good Paragraph with…

• Good Bullet
• Good Bullet
• Good Bullet

Designer tips you can apply to your UI:

• Group information in small logical parts

Principle 3. Jackob Nielsen Law, Mental Models, and User Expectation

One of the founding fathers in Usability testing Jacob Nielsen finds out, that users expect your website to work as other websites they previously visited.

User form Mental Models about the way interfaces should work.

By adopting existing User Patterns in your interface you reduce cognitive load and use already formed mental models, so the user won’t have to learn your interface from scratch.

This doesn’t mean that we should become sort of UI conservatives, that only use only widely accepted patterns. It would make UI design really boring activity :)

However, as Jony Ive once told: The purpose of design is to build something new, but that’s strangely familiar.

This is what designers should do: utilize mental models that a person has and adapt it to the new design pattern.

Considering the mental models of users becomes of major importance when you plan to redesign something. When you create new UX, you must be sure that your interface fits already existing mental models users learned by using your product.

Designer tips you can apply to your UI:

• Utilize UI patterns to make your interface more intuitive
• When you build a new UI pattern try to fit it to patterns users already know