Nowadays, we are flooded with visual content from every direction, and it is relatively easy to get overwhelmed. That is why, when creating a user-centric product, it's crucial to prioritize its comprehensibility for users instead of burdening them with additional content.
Users must invest the cognitive effort required for learning whenever they engage with an interface. This effort is also referred to as the cognitive load. When cognitive load becomes too high, it leads to fatigue and rapid loss of interest. Remembering to reduce users' mental processing demands while designing any interface can, therefore, significantly improve your product's performance.
Let's begin with a bit of psychological context; there are three types of cognitive load. The intrinsic cognitive load describes the difficulty of a task itself. Extraneous cognitive load is the additional mental effort that is not directly tied to the task as such. Germane cognitive load is responsible for forming and processing mental schemas. 
We, as designers, can focus mainly on the extraneous cognitive load. An inappropriate use of font or graphic elements can unnecessarily cause increased demand for mental processing. As a result, the user becomes frustrated, confused, and likely to abandon the task or product. Therefore, to keep the customers satisfied and returning to the interface, we must consider some basic rules to manage this mental effort. 
Three key principles to make the design more easily processable
Knowing your users
Firstly, to create an optimally comprehensible design solution, it is essential to know the users properly. Although it might sound like a bit of a cliche, it is truly a way to earn their trust and understand them. The user’s behavior is not driven only by conscious and rational decisions; instead, subconscious mental frameworks and beliefs play a significant role in decision-making. Therefore, both aspects have to be considered when creating a user-centered design.  
Enabling easier interaction between the user and the design involves using familiar patterns and layouts the users are used to encountering in comparable interfaces. That way, we can prevent confusion caused by an unexpected placement of a UI element or a functionality that does not follow the usual characteristics. Similarly, less technical language creates more clarity on the users' end.  
Providing a sense of progress to the users is also essential to keep them interested and motivated in using your UI. For example, when filling out a questionnaire, one feels way more at ease when informed about which steps are already completed and which are yet to be accomplished. Motivating the user with brief, one-time "great job" praises proves effective, as they induce minimal stress instead of more complex gamification strategies.  
Recognition rather than recall
The second rule is to count on users' recognition rather than recall. According to Miller's law, humans can hold 7 ± 2 pieces of information in their short-term memory. Therefore, we should not rely on the users' ability to remember a large amount of data. Instead, recognition – displaying the information, requires way less cognitive effort. An example of this can be subtly differentiating already visited links or using breadcrumbs indicating the previous steps leading to the current state. 
Utilizing widely recognized iconography can also be a great way to present information in a simplified manner. However, the effect can be quite the contrary when using less familiar icons. It might require additional cognitive effort to recall or deduce meaning depending on the user's prior experience. It is also essential to consider the cultural background of the target audience, as different symbols have various meanings across cultures. A solution to that is accompanying the graphics with a clear label to facilitate quicker understanding. 
Less is more
The third core principle is the good old: less is more. That involves a reduction of redundant visual clutter and data that do not bring any informational value. Similarly, eliminating unnecessary steps assures users are not overwhelmed and stay focused longer. However, ensuring that simplicity doesn't compromise clarity or comprehension is crucial. A monotonous design without much color or graphic elements at any cost might not be a step forward. When faced with an overly uniform UI, the human brain might tire quickly due to the lack of differentiation. 
Simplification can also be achieved by providing a limited amount of available choices. When the user faces a selection of too many choices, it is more likely to create decision paralysis caused by increased cognitive load. Additionally, clearly indicating which options are selected and which are available simplifies the users' interaction. Arranging the options into logical groups can also improve their understandability for the user. 
Sometimes, it is easy to get carried away during the design process with new and exciting ideas, inadvertently overlooking a crucial element—the functionality. The final design should be aesthetically pleasing but also primarily easy to understand, causing minimal cognitive load to the users.
In the end, the user should almost perceive the design subconsciously rather than being distracted by bold design choices. Here at Kontrolka, we always keep this in mind and create a design that addresses the specific needs and preferences of the intended users. The principles discussed above provide a great foundation applicable to user-centered design across industries. However, it is important always to consider the distinct context and requirements for which we are designing.
Kontrolka is a young team of HMI experts who strive to push user experience to its limits by developing innovative solutions for tomorrow's technology. We inspire and motivate our clients to achieve success.