5 essential UI/UX laws, for product managers!

Most Articles I read about UI/UX laws were for product designers, and if you are a designer or you like to read more about these laws, I suggest to check "UX laws: 21 principles for creating winning designs" from Maze. But in this article, we are going to define 5 essential UI/UX laws, give real life examples, check the importance of these laws, and explain how to measure them from product manager POV.

1- Jacob's Law

Jacob's Law is a principle in user experience (UX) design which states that "users spend most of their time on other sites." As a result, they prefer your site to work the same way as all the other sites they already know. This principle emphasizes the importance of leveraging familiar design patterns to create a more intuitive user experience.

Key Points of Jacob's Law:

1. Consistency: Users expect websites to behave in a consistent manner. Familiar navigation structures, common button placements, and standard icons help users feel more comfortable and reduce the learning curve.

2. Efficiency: By aligning your design with widely accepted standards, you can reduce the time it takes for users to complete tasks on your site. This leads to a more efficient and pleasant experience.

3. Usability: Leveraging common design patterns enhances usability. Users do not need to learn new interfaces or adapt to unconventional designs, making it easier for them to achieve their goals.

4. Trust: Familiarity breeds trust. When users recognize familiar elements and patterns, they are more likely to trust your site and feel confident in navigating it.

Practical Applications:

• Navigation: Use standard navigation menus and placement. For example, having a horizontal navigation bar at the top of the page or a vertical menu on the left side.

• Icons: Use universally recognized icons for common actions like search (magnifying glass), settings (gear), or home (house).

• Forms: Design forms that follow common structures, such as placing labels above input fields and using standard field types for common inputs (e.g., email, phone number).

• Responsive Design: Ensure your site is responsive and follows common responsive design patterns to provide a consistent experience across different devices.

By adhering to Jacob's Law, designers can create more user-friendly interfaces that meet users' expectations and improve overall satisfaction.

Why is it important for PMs:

• Leverages Familiarity: Designing interfaces that align with users’ existing knowledge and habits reduces the learning curve and increases usability.

• Builds Trust: Consistent and familiar design patterns make users feel more comfortable and confident using the product.

2- Fitts's Law

Fitts's Law, formulated by psychologist Paul Fitts in 1954, is a predictive model of human movement primarily used in human-computer interaction and ergonomics. It describes the time required to move to a target area as a function of the distance to the target and the size of the target. The law is widely applied in the design of user interfaces to enhance usability and efficiency.

Key Principles:

1. Target Size: Larger targets are easier and quicker to hit because they require less precision.

2. Target Distance: Closer targets are easier and quicker to hit because they require less movement.

3. Movement Time: The time to acquire a target increases with the distance to the target and decreases with the target size.

Example Scenarios:

• Navigation Bars: A navigation bar with large, well-spaced buttons will be easier and faster for users to navigate compared to one with small, closely packed buttons.

• Call-to-Action Buttons: A prominent, large call-to-action button increases the likelihood of user interaction compared to a small, inconspicuous button.

• Touch Interfaces: For touch screens, larger touch targets reduce the likelihood of errors and make the interface more accessible, particularly for users with larger fingers or those with motor impairments.

Fitts's Law provides a valuable framework for making design decisions that enhance the usability and efficiency of user interfaces, ultimately leading to better user experiences.

Why is it important for PMs:

• Improves Usability: Ensuring that important buttons and interactive elements are large and easy to reach makes the product more user-friendly.

• Enhances Efficiency: Reducing the time and effort needed for users to interact with the product increases productivity and satisfaction.

3- Hick's Law

Hick's Law, named after British psychologist William Edmund Hick, describes the time it takes for a person to make a decision as a result of the possible choices they have. Specifically, it states that increasing the number of choices will logarithmically increase the decision time. This principle is essential in UI/UX design for creating interfaces that facilitate quick and efficient user interactions.

Key Principles:

1. Decision Time: The time required to make a decision increases with the number of choices available.

2. Choice Complexity: More complex or ambiguous choices will take longer to process, even if the number of choices is small.

3. Logarithmic Growth: Decision time increases logarithmically, meaning that the effect of each additional choice diminishes as the number of choices grows.

Example Scenarios:

• E-Commerce Websites: On an e-commerce site, categorizing products into well-defined categories and subcategories can help users find products more quickly than presenting a long list of all available products.

• Settings Menus: A settings menu that groups related settings into categories (e.g., display, sound, privacy) allows users to navigate and find specific settings more efficiently.

• Onboarding Processes: Simplifying onboarding steps by breaking them into smaller, more manageable tasks can help users complete the process more quickly and with less frustration.

Why is it important for PMs:

• Streamlines Decision-Making: Simplifying choices helps users make decisions faster and reduces cognitive overload.

• Improves User Experience: A simpler interface leads to a more pleasant and less frustrating user experience, which can improve user retention and satisfaction.

4- Miller's Law

Miller's Law, proposed by cognitive psychologist George A. Miller in 1956, revolves around the concept of human memory limitations. It suggests that the average person can hold about 7 (plus or minus 2) items in their working memory at one time. This law is foundational in understanding how to design information and user interfaces that align with human cognitive capabilities.

Key Principles

1. Working Memory Capacity: The human brain can only process and remember a limited amount of information at a time, typically around 7 items.

2. Chunking: Organizing information into larger, meaningful units or "chunks" can help users remember and process more information effectively.

3. Cognitive Load: Reducing the amount of information presented at once can lower cognitive load and improve comprehension and usability.

Example Scenarios

• E-Commerce Checkout: Instead of presenting all checkout fields on one page, use a multi-step form that breaks the process into smaller, more manageable steps (e.g., shipping information, payment details, review order).

• Onboarding: For new user onboarding, provide a series of small, guided steps or tutorials instead of overwhelming users with all information at once.

• Settings Menus: In application settings, group related settings under specific categories (e.g., display, notifications, privacy) rather than listing all settings on a single page.

Miller's Law highlights the importance of considering human memory limitations in UI/UX design. By presenting information in small, manageable chunks and organizing related items together, designers can create more user-friendly and effective interfaces. Understanding and applying this principle helps reduce cognitive load, enhance usability, and improve the overall user experience.

Why is it important for PMs:

• Reduces Cognitive Load: Presenting information in manageable chunks prevents users from feeling overwhelmed, making the product easier to use.

• Enhances Learnability: Simplifying information presentation helps users learn how to use the product more quickly and effectively.

5- Tesler’s Law

Tesler’s Law, also known as the Law of Conservation of Complexity, was formulated by Larry Tesler, a pioneer in human-computer interaction. This principle states that for any system, there is a certain amount of complexity that cannot be reduced. The goal in design is to manage and handle complexity effectively, often by transferring it from the user to the system.

Key Principles

1. Irreducible Complexity: Some level of complexity is inherent and cannot be eliminated entirely; it must be managed.

2. User Burden: Shifting complexity away from the user and into the system can make the user experience more seamless and intuitive.

3. System Design: Designers and developers should strive to absorb the complexity within the system to simplify user interactions.

Example Scenarios

• E-Commerce Checkout: Simplify the checkout process by pre-filling user information if they have previously logged in, providing clear steps, and offering multiple payment options in a user-friendly format.

• Onboarding: Design an onboarding process that guides new users through essential features step-by-step, providing contextual tips and avoiding overwhelming them with all functionalities at once.

• Form Design: Implement forms that dynamically adjust based on user input, hiding irrelevant fields and providing instant feedback to ensure accurate and efficient completion.

Tesler’s Law emphasizes the importance of managing complexity in system design. By shifting complexity from the user to the system, designers can create more intuitive and user-friendly interfaces. This principle helps in reducing cognitive load, enhancing usability, and improving the overall user experience. Understanding and applying Tesler’s Law allows for the development of systems that are not only powerful but also accessible and efficient for users.

Why is it important for PMs:

• Manages Complexity: Shifting complexity from the user to the system makes the product more intuitive and user-friendly.

• Boosts User Satisfaction: By automating tasks and simplifying interactions, users can achieve their goals with less effort, leading to higher satisfaction.

By incorporating these UI/UX laws into their workflow, product managers can ensure that their products are not only functional but also provide a seamless and satisfying user experience.