User experience design has its conceptual roots in cognitive and behavioral psychology and it is a blueprint of a human being's interaction with a machine. Their interaction, behavior and emotions can add much more worth value to understand them in the product building process.

Human psychology is a vital part of the User Experience design process. UX Designers need to be apt with understanding the implementation, usage and impact of their designs on the users. All of the users make their digital decisions based on their cognition, neurology, social and cognitive psychology and human-computer interaction. Not only does this help in tracking the user's decisions and behavior but also in making effective iterations to the overall design.

Different principles of psychology impact human behavior and decisions. This is a great way to design interfaces to produce desired responses and actions from the target audience.

The 21 laws of UX are divided into 4 subcategories. Let's have a brief look over all these.

Category 1: Heuristic

1. Aesthetic-Usability Effect

If users find the interface visually appealing, they are likely to ignore minor issues with the usability. This property helps in masking usability issues while the interface is being tested for usability. By definition, it refers to a user's tendency to perceive attractive products as more usable. Good visual appeals help the users build a positive emotional response to your website and ignore minor usability issues.

2. Fitt's Law

This law states that the amount of time required to move a cursor or pointer to a target area is a function of the distance to the target divided by the size of the target. Hence, if the distance is longer and the target size is smaller, the longer it would take. This law is widely used in the world of UX and UI. This law advises keeping the interaction buttons larger in size and task-related buttons as short as possible.

3. Goal-Gradient Effect

Users are motivated by how close they are to achieve their goals. Users can be motivated to achieve their goals when they complete smaller objectives. Providing artificial progress towards a goal helps ensure increase the motivation to complete that task. When a clear indication of progress is indicated, it pushes the user to move forward in the process.

4. Hick's Law

The more complex a set of choices is and the larger the options are, the more difficult it becomes to make a decision for a user. It is important to minimize choices when response times are critical to increase decision time and break complex tasks into smaller objectives to decrease the cognitive load. However, make sure that in an effort to make things simpler, you don't get to a point where the interface loses its purpose and function.

5. Jakob's Law

If users spend most of their time on other sites, it means they want your site to be similar to the ones they are already looking at. When it comes to similar service providers, users usually transfer their expectations in terms of appearance. This law allows designers to create superior user experiences by leveraging the existing mental models.

6. Miller's Law

This law states that an average person can only keep around 7 items in their working memory.

“The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information.”1 Miller

This law leads to the conclusion that bits that are the basic units of information do not affect the memory span as much as the number of information chunks being memorized. This does not justify a designer's argument on unnecessary design limitations. Miller's law advocates the organization of content into smaller chunks to help the users process, understand and memorize the flow of an interface easily.

7. Parkinson's Law

Parkinson’s Law is the adage that work will expand to fill the time allotted for its completion. This holds true for a number of our routine examples. Human mind processes in a way to prioritize urgent tasks that the mind interprets as more important and suppresses the importance of other tasks. In such cases, even the simplest tasks take a hefty amount of time to complete.

Category 2: Principle

8. Doherty Threshold

Doherty Threshold is an objective for design and development specialists to keep the users engaged while they interact with a computer or interface. This principle indicates that if the response time increases the 400 ms (4/10ths of a second), the user loses interest. It was discovered through this that the longer the response time, the more time users take to think of the next task thus, reducing productivity.

9. Occam’s Razor

Occam's Razor advocates that the simplest solution is always the best one. This principle helps designers to make sure that their designs are simple, yet powerful and enable a user to complete their action. When designs are over-crowded in trying to add good elements to the same interface, it deconstructs a design and distorts its functionality.

10. Pareto Principle

The Pareto Principle states that 80% of consequences come from 20% of the causes. It does not, however, apply to all scenarios, and it is observed that most things in life are not evenly distributed. This principle has special application to the client-service-based businesses. This helps UX designers to identify and fix problems that may cause issues and act as a hindrance for the users to complete their actions on a digital platform.

11. Postel's Law

Postel's law is also known as the robustness principle. It is stated as:

Be conservative in what you do, be liberal in what you accept from others.

This principle aims at maximizing a system's tolerance for small incompatibilities. Service providers of the same industry might be following the same protocol but the way they appear might differ. Given this, the first scenario of the principle which implies giving room for variations makes sense.

12. Tesler’s Law

Tesler's law, also known as the law of conservation states that for any system, there is a certain amount of complexity that cannot be reduced. This law points towards the importance of creating ease for the user. It is argued that if needed, it is better for an engineer to spend an extra week trying to minimize the complexities rather than a user spending an extra minute to complete their action because of that complexity.

Category 3: Gestalt

13. Law of Common Region

The principle of common region states that elements that are placed in close proximity to each other are perceived to have some common functionality and purpose. One method to create the common region effect is adding a border around an element or group of elements. The human mind has an innate disposition to perceive patterns in the stimulus based on certain rules.

14. Law of Proximity

The law of proximity states that the human eye perceives elements that are close together to be connected with each other while elements that are separate from each other are perceived to be separate from each other. This holds true for interface design. It helps establish a relationship with the nearby objects. This law help0s users understand and organize information faster and more efficiently.

15. Law of Prägnanz

The law of Prägnanz states that people will perceive and interpret ambiguous or complex images in the simplest form possible because it is the interpretation that requires the least cognitive effort. The human eye likes to find simplicity and order in complex shapes because it prevents us from becoming overwhelmed with information. Research confirms that people are better able to visually process and remember simple figures than complex figures.

16. Law of Similarity

The human eye tends to perceive similar elements in a design as a complete picture, shape, or group, even if those elements are separated. Elements that are visually similar will be perceived as related. Color, shape, and size, orientation and movement can signal that elements belong to the same group and likely share a common meaning or functionality. Ensure that links and navigation systems are visually differentiated from normal text elements.

17. Law of Uniform Connectedness

Elements that are visually connected are perceived as more closely related than elements with no connection. Group functions of a similar nature so they are visually connected via colors, lines, frames, or other shapes. Alternately, using tangible references among all the elements also create a visual connection. The use of uniform connectedness to show context or to emphasize the relationship between similar items is encouraged.

Category 4: Cognitive Bias

18. Peak-End Rule

Peak-End Rule advocates that people judge an experience largely based on how they felt at its peak and at its end, rather than the total sum or average of every moment of the experience. Designers need to pay close attention to the most intense points and the final moments of the user journey and identify the moments when their product is most helpful, valuable, or entertaining. The purpose of design is to delight the end-user and overpower any negative experiences.

19. Serial Position Effect

Human cognition has a propensity to best remember the first and last items in a series. Placing the least important items in the middle of lists can be helpful because these items tend to be stored less frequently in long-term and working memory. Positioning the key actions on the far left and right within elements such as navigation can increase memorization.

20. Von Restorff Effect

The Von Restorff effect, also known as The Isolation Effect, predicts that when multiple similar objects are present, the one that differs from the rest is most likely to be remembered. In designing interfaces, it is advised to make key actions visually distinctive. Use restraint when placing emphasis on visual elements to avoid them competing with one another and to ensure salient items don’t get mistakenly identified as ads.

Here, it is crucial to remember the principle of adaptability which advices to not exclude those with a color vision deficiency or low vision by relying exclusively on color to communicate contrast. Carefully consider users with motion sensitivity when using motion to communicate contrast.

21. Zeigarnik Effect

People remember incomplete or interrupted tasks better than completed tasks. Invite content discovery by providing clear signifiers of additional content. Providing artificial progress towards a goal will help to ensure that users are more likely to have the motivation to complete that task. Provide a clear indication of progress in order to motivate users to complete tasks.

Conclusion

The laws of UX act as a complete guide to designers while building interfaces. These laws and principles act as guidelines to ensure that design specialists create designs that translate a brand's intention towards its target audience in a crisp and clear manner. The study of heuristic psychology has shaped these laws while keeping in mind how the human brain works and interprets information. These laws, if kept in mind while designing interfaces come out to be the greatest guide for coming up with exceptional work.

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