The effect of cognitive load in UX

Discussing cognitive load and how will it affect the usability

Do you consider human needs and human brain capacity or memory while designing?

Just like computers, the human brain also has processing power and memory capacity. Too much data and forcing the brain to accommodate all these data frustrate the user and leads them to abandon the task. The short term memory of our brain has limitations. It varies from users to users. Psychologist says that an average user can store 7 chunks of information in his short term memory at a time. Adding more than this information leads to an increase in cognitive load. This not means that we can add only 7 menus in a navigation bar. We don’t need to remember the menu items. It is always there on the navigation bar. The menu items have relied on Recognition rather than recall (usability heuristics).

Consider we have two screens of the mobile app, the first screen has some instructions that to be followed on the second screen. According to our short-term memory capacity providing overloaded instructions on the first page increases the cognitive load and forcing people to read instructions again and again.

Good user experience is good for everyone, not only for those people who have a large short term memory. So, a general good practice of design is to limit the burden put on the users’ memory.

The term “cognitive load” was originally coined by psychologists to describe the mental effort required to learn new information.

How cognitive load affects Usability?

1. Mental Model

When designing a product (website), the user has a mental model of how the website works from their past experience. Therefore designing a new one with a huge difference in layout or labels leads to thinking in users. This increases the cognitive load. While using the layout and labels that are familiar to users will reduce the new learning of users and thereby decreases the cognitive load. If the website has a huge difference from the user’s mental model, then the cognitive load will increase and interaction cost will increase.

2. Affordances and signifiers

Here I am considering mobile apps to explain how affordances and signifiers affect the cognitive load. We all saw the bottom navigation bar in mobile apps. To increase the aesthetics of the app, some designers will remove the label(signifier) of the icons(affordance) from the navigation bar.

The screen of an app from playstore

Does anyone understand the purpose of the icon inside the red rectangle? Maybe someone understands the purpose or meaning of other icons. This will leads the user to think about the purpose of the icon. Thinking about this increases the cognitive load and will decrease usability.

Designing with apt affordances and signifiers will reduce the cognitive load and maximize usability.

3. Chunking content

In the field of user-experience design, ‘chunking’ usually refers to breaking up content into small, distinct units of information.

Chunking has a much important role in reducing cognitive load.

I believe that all of you understood how chunking data can reduce cognitive load. It is easy to remember the above number after chunking. Chunking is critical for presenting content that users can comprehend and remember easily.

4. Visual design The visual design also has a role in cognitive load. What about if a site contains too small font size and blurred or irrelevant images? For example, if one site contains an image that has no relation to its content. Then users get confused about that and it leads to an increase in cognitive load.

It is important that designers should reduce cognitive load while designing. By reducing the cognitive load we can increase usability. Thereby less interaction cost. So the user can achieve their task without any frustration and the user loves to use our product again and again. One of the factors that influence user experience is valuable. By decreasing the cognitive load we can increase the valuable(business) of our product.

Minimum cognitive load=Maximum Usability

Thanks for reading.

Reference:nngroup. Your valuable feedbacks are appreciated.