The 21 Laws of User Experience (UX) are a set of principles that provide a framework for creating effective and engaging user experiences. These laws were developed by user experience consultant and author, Jon Yablonski, and are based on the principles of psychology, design, and human behavior. In this article, we will explore each of the 21 laws and how they can be applied to UX design.
1. Fitts’s Law
Fitts’s law is a fundamental principle of human-computer interaction that predicts the time it takes for a user to point at an object on a screen or any other interactive interface. The law states that the time required to move to a target is a function of the target’s size and distance from the starting point. In other words, the larger the target and the closer it is to the user’s starting point, the faster and more accurate the movement will be.
Fitts’s law is widely used in the design of user interfaces, particularly for touchscreens and other input devices that require precise targeting. Designers can apply Fitts’s law to optimize the size and placement of interactive elements, such as buttons and links, to improve the overall usability and efficiency of the user interface.
2. Hick’s Law
Hick’s Law, also known as the Hick-Hyman Law, is a psychological principle that describes the relationship between the number of options a person has and the time it takes to make a decision. The law states that as the number of choices increases, the time it takes to make a decision also increases. This is because the brain has to process and evaluate each option before making a choice.
Hick’s Law has important implications for user interface design, as too many choices can overwhelm users and lead to decision paralysis. Designers can apply Hick’s Law by simplifying the user interface and reducing the number of options presented to users, making it easier and faster for them to make a decision. By reducing the cognitive load required to make decisions, designers can create more intuitive and efficient user experiences.
3. Miller’s Law
Miller’s Law, also known as The Magical Number Seven, Plus or Minus Two, is a cognitive principle that describes the limited capacity of human working memory. The law states that the average person can only hold seven (plus or minus two) pieces of information in their working memory at one time.
Miller’s Law is an essential consideration for user interface designers, as it suggests that users may struggle to process and remember large amounts of information presented to them at once. Designers can apply Miller’s Law by breaking up complex information into smaller, more manageable chunks and presenting it in a way that is easy to understand and remember. This can improve the overall usability of the interface, reducing cognitive load and enabling users to focus on completing tasks more efficiently.
4. Jakob’s Law
Jakob’s Law is a user experience design principle that states that users expect a website or application to function in the same way as other sites and apps that they use regularly. This means that users are more comfortable with interfaces that are familiar and follow established design patterns.
Jakob’s Law suggests that designers should aim to create interfaces that are consistent with user expectations, both in terms of layout and functionality. This can help to improve the overall user experience by reducing confusion and enabling users to complete tasks more efficiently. To apply Jakob’s Law, designers must understand the common design patterns used in their industry and aim to create interfaces that are in line with those patterns while also being unique and innovative.
6. Tesler’s Law
Tesler’s Law, also known as The Law of Conservation of Complexity, states that every system has a certain amount of complexity that cannot be eliminated, but can only be moved around. This means that when designers simplify one aspect of a system, complexity is often shifted to another area.
In the context of user experience design, Tesler’s Law suggests that designers should aim to minimize complexity wherever possible, but also be aware of how changes in one area can affect other parts of the system. By balancing the complexity of different elements within a system, designers can create interfaces that are intuitive, user-friendly, and efficient. For example, a website may simplify the checkout process by reducing the number of form fields but may need to provide additional information or support in other areas to compensate for the reduced complexity. By applying Tesler’s Law, designers can optimize the usability and effectiveness of their interfaces while balancing the inherent complexity of the system.
7. Parkinson’s Law
Parkinson’s Law is the adage that work expands to fill the time available for its completion. This principle suggests that tasks will often take up more time than necessary if there are no constraints or deadlines in place.
In the context of user experience design, Parkinson’s Law highlights the importance of setting clear limits on the time it takes to complete a task. By using helpful features such as autofill, to save the user time, you allow them to complete purchases, booking and other functions quicker by preventing task inflation.
8. Postel’s Law
Postel’s Law, also known as the Robustness Principle, states that programs should be conservative in what they send and liberal in what they accept. This principle suggests that software should be designed to work with a wide range of inputs, even if those inputs do not conform to strict standards or expectations.
In the context of user experience design, Postel’s Law emphasizes the importance of flexibility and adaptability in software interfaces. By designing systems that can handle a variety of user inputs and account for unexpected behavior, designers can create interfaces that are more robust and user-friendly. However, this principle also highlights the need for clear and consistent communication between software components, to ensure that unexpected inputs do not cause errors or crashes. Overall, Postel’s Law encourages designers to prioritize the user experience by designing software that is intuitive, flexible, and tolerant of variation.
9. Law of Similarity
The Law of Similarity is a principle of Gestalt psychology that suggests that people tend to group similar elements together, perceiving them as a single entity or pattern. In the context of user experience design, the Law of Similarity can be applied to visual design and information architecture, helping designers to create more intuitive and easily navigable interfaces. By grouping similar elements together, designers can create visual cues and patterns that allow users to quickly identify related information or functions.
This principle is often used in interface design to create visual hierarchies, with related elements grouped together and visually differentiated from other elements on the page. The Law of Similarity can also be used in typography and iconography, with consistent visual cues and styles used to indicate related information or actions. Overall, the Law of Similarity highlights the importance of visual consistency and organization in creating effective user interfaces.
10. Law of Proximity
The Law of Proximity is a principle of Gestalt psychology that suggests that people tend to group together elements that are close to each other. This principle can be applied to user experience design to create more intuitive and easily navigable interfaces. By placing related elements in close proximity to each other, designers can create visual cues that allow users to quickly identify related information or functions.
This principle is often used in interface design to create visual hierarchies, with related elements grouped together and visually differentiated from other elements on the page. The Law of Proximity can also be used to create emphasis and focus on specific elements by placing them in close proximity to each other or separating them from other elements on the page. Overall, the Law of Proximity highlights the importance of spatial relationships and organization in creating effective user interfaces.
11. Law of Common Region
The Law of Common Region is a principle of Gestalt psychology that suggests that elements that are located within the same region or boundary tend to be perceived as a single unit or group. This principle can be applied to user experience design to create more intuitive and easily navigable interfaces. By grouping related elements together within a common region or boundary, designers can create visual cues that allow users to quickly identify related information or functions.
This principle is often used in interface design to create visual hierarchies, with related elements grouped together and visually differentiated from other elements on the page. The Law of Common Region can also be used to create emphasis and focus on specific elements by placing them within their own region or boundary. Overall, the Law of Common Region highlights the importance of grouping and organization in creating effective user interfaces.
12. Law of Uniform Connectedness
The Law of Uniform Connectedness is a principle of Gestalt psychology that suggests that elements that are visually connected to each other are perceived as a single unit or group, even if they are not physically close to each other. This principle can be applied to user experience design to create more intuitive and easily navigable interfaces. By visually connecting related elements through the use of lines, shapes, or other visual cues, designers can create a sense of unity and coherence that allows users to quickly identify related information or functions.
This principle is often used in interface design to create visual hierarchies, with related elements connected through lines or other visual cues to emphasize their relationship. The Law of Uniform Connectedness can also be used to create emphasis and focus on specific elements by visually separating them from other elements on the page. Overall, the Law of Uniform Connectedness highlights the importance of visual relationships and connections in creating effective user interfaces.
13. Law of Prägnanz
The Law of Prägnanz, also known as the Law of Good Figure or the Law of Simplicity, is a principle of Gestalt psychology that suggests that people tend to perceive and interpret complex images or stimuli in the simplest and most organized way possible. This principle can be applied to user experience design to create interfaces that are visually simple, organized, and easy to understand. By using clear and concise visual elements, designers can create a sense of order and structure that allows users to quickly identify important information or functions.
The Law of Prägnanz is often used in interface design to create visual hierarchies, with important elements placed in prominent positions and less important elements visually de-emphasized. This principle is also important in designing logos, icons, and other visual elements that should be immediately recognizable and easily understood. Overall, the Law of Prägnanz highlights the importance of simplicity and clarity in creating effective user interfaces.
14. Zeigarnik Effect
The Zeigarnik Effect is a psychological phenomenon that describes the tendency for people to remember incomplete tasks or unfinished activities more easily than completed ones. The effect is named after Soviet psychologist Bluma Zeigarnik, who observed that waiters in a restaurant were better at remembering orders that were still in progress than those that had already been served.
This effect has important implications for user experience design, as it suggests that users may be more likely to remember and return to an application or website if they have unfinished tasks or goals. To apply the Zeigarnik Effect in design, designers can create features that encourage users to complete tasks or provide reminders of incomplete tasks to increase the chances that users will return to the application or website to finish their work. For example, a shopping website may provide reminders for items left in the user’s shopping cart, encouraging the user to return and complete the purchase.
15. Von Restorff Effect
The Von Restorff Effect is a psychological phenomenon that suggests that an item that is distinct from its surroundings is more likely to be remembered. Also known as the “isolation effect,” this principle suggests that people tend to pay more attention to unique or unusual items than to those that are similar to their surroundings.
In the context of user experience design, designers can apply the Von Restorff Effect to improve the visibility and memorability of important elements, such as calls-to-action, key messages, or branding. By making these elements visually distinct from their surroundings, designers can ensure that they stand out and are more likely to be remembered by users. For example, a website may use a bold font, bright color, or contrasting background to make a call-to-action button stand out from other page elements. Applying the Von Restorff Effect can help designers to create interfaces that are more engaging, memorable, and effective.
16. Goal-Gradient Effect
The Goal-Gradient Effect is a phenomenon in psychology that refers to the tendency of individuals to become more motivated and goal-oriented as they approach a goal or objective. In other words, people tend to increase their efforts and accelerate their progress as they get closer to achieving a desired outcome. This effect is often observed in consumer behavior, where individuals may increase their spending or consumption as they approach a reward or benefit, such as a loyalty program or a discount.
The Goal-Gradient Effect has important implications for user experience design, as it can be used to motivate users to engage more with a product or service by providing visible progress towards a goal. For example, a progress bar that shows how close a user is to completing a task can help to motivate them to continue working towards their goal. By understanding and leveraging the Goal-Gradient Effect, designers can create more effective and engaging experiences for users.
17. Aesthetic-Usability Effect
The aesthetic-usability effect is a phenomenon in which users perceive aesthetically pleasing designs as more usable and efficient than less attractive ones. In other words, users tend to associate a visually pleasing interface with a high level of usability, even if it might not be the case.
This effect highlights the importance of aesthetics in the design process and shows that aesthetics can play a significant role in user experience. Designers should strive to create visually appealing designs that are also intuitive and functional to ensure a positive user experience.
18. Occam’s Razor
Occam’s Razor is a principle in philosophy that states that when faced with multiple explanations for a phenomenon, the simplest explanation is usually the correct one. In UX design, Occam’s Razor can be applied to ensure that the design is clear, concise, and easy to use. This means that unnecessary elements should be eliminated, and only the essential elements should be included in the design.
The principle of Occam’s Razor is particularly relevant in the age of mobile devices, where screen space is limited, and users have short attention spans. By adhering to the principle of Occam’s Razor, UX designers can create designs that are more intuitive, user-friendly, and efficient. This can lead to increased user satisfaction, engagement, and ultimately, the success of the product or service.
19. Pareto Principle
The Pareto Principle, also known as the 80/20 rule, is a principle that suggests that 80% of effects come from 20% of causes. This principle can be applied in various fields, including economics, business, and engineering.
In the context of user experience design, the Pareto Principle suggests that designers should focus on the 20% of features or functionality that will have the most significant impact on the user experience. By prioritizing these features, designers can create an interface that is efficient, effective, and user-friendly. For example, a website may focus on improving the top 20% of pages that receive the most traffic, rather than spending resources on pages that are rarely visited. Applying the Pareto Principle can help designers to optimize their resources, streamline their design process, and create interfaces that deliver maximum value to users.
20. Doherty Threshold
The Doherty Threshold, also known as the “Instantaneous Response Time,” is a principle in UX design that refers to the maximum delay a user can tolerate between a command and the system’s response. The principle was introduced by Walter Doherty, who observed that when the response time of a system exceeds 400 milliseconds, users start to lose focus and attention, which can result in frustration and dissatisfaction.
The Doherty Threshold is an essential consideration for UX designers as it can significantly impact user experience and overall product success. To ensure that the Doherty Threshold is met, designers need to focus on optimizing response times, reducing latency, and improving system performance. By doing so, designers can create more responsive and engaging products that meet user needs and expectations.
21. Peak-End Rule
The Peak-End Rule is a psychological principle that states people tend to judge an experience based on how they felt at its peak and at its end. The theory was introduced by psychologist Daniel Kahneman, who found that people’s memories of an experience are determined by how they felt during the most intense part of the experience and how they felt when it ended. In UX design, the Peak-End Rule suggests that designers should focus on creating peak moments and ensuring that the final moments of a user’s experience are positive. This can be achieved through various means, such as providing delightful micro-interactions, simplifying the user journey, and offering clear and concise feedback. By applying the Peak-End Rule in UX design, designers can create more memorable and satisfying experiences for users that leave a lasting positive impression.
In conclusion, the 21 Laws of UX provide a set of guidelines that can help designers create user-centered products and interfaces that are both effective and enjoyable to use. By understanding these principles and applying them in their designs, designers can create experiences that are intuitive, aesthetically pleasing, and efficient. While not all 21 Laws will apply to every project, they provide a solid foundation for any UX design project. The Laws remind us that design is not just about aesthetics, but also about human behavior and psychology. By keeping the user in mind and applying these principles, designers can create products and interfaces that not only meet users’ needs but also delight them. Ultimately, the 21 Laws of UX are a valuable resource for any designer who wants to create user-centered designs that are both effective and enjoyable to use.