1. Aesthetic-Usability Effect

Summary: Users are more likely to find visually attractive designs more usable, even if the actual functionality is unchanged. Good aesthetics can enhance the overall user experience by making users more tolerant of minor usability issues and more satisfied with the interaction.

Example: Apple’s clean and sleek product designs, which users find more enjoyable to interact with due to their high aesthetic appeal.

Actionable Advice:

- Enhance visual appeal through careful selection of colors, typography, and imagery.

- Ensure the design is aesthetically pleasing without compromising functionality.

- Conduct user testing to balance aesthetics and usability.

2. Doherty Threshold

Summary: When the interaction between user and system occurs within 400 milliseconds, users are more engaged, leading to higher productivity. Quick system responses keep the user's attention and provide a seamless experience.

Example: Instant search suggestions on Google, where results appear as the user types, keeping them engaged.

Actionable Advice:

- Optimize performance to ensure response times are within the 400ms threshold.

- Use asynchronous processing to handle large data sets without slowing down the user interface.

- Provide visual feedback during longer operations to maintain user engagement.

3. Fitts’s Law

Summary: The time required to move to a target area is a function of the distance to the target and the size of the target. Larger and closer targets can be selected faster and more accurately.

Example: Large touch targets on mobile apps make it easier for users to interact without precision errors.

Actionable Advice:

- Increase the size of important buttons and clickable areas.

- Place frequently used buttons closer to where users’ hands naturally rest.

- Ensure touch targets have ample spacing to avoid accidental clicks.

4. Goal-Gradient Effect

Summary: The closer users are to completing a goal, the more motivated they become to finish it. Showing progress towards a goal can enhance user motivation and engagement.

Example: Progress bars in online surveys or e-commerce checkout processes that show users how close they are to completion.

Actionable Advice:

- Use progress indicators to visually display advancement towards a goal.

- Break tasks into smaller, more manageable steps to maintain momentum.

- Provide rewards or positive feedback as users make progress.

5. Hick’s Law

Summary: The time it takes for a person to make a decision increases with the number and complexity of choices. Simplifying choices can help users make decisions faster and reduce cognitive load.

Example: Simplified menus on websites like Google, which reduce the number of options presented to the user at one time.

Actionable Advice:

- Limit the number of choices presented to the user.

- Group related options together to make decision-making easier.

- Use progressive disclosure to reveal information gradually, avoiding overwhelming the user.

6. Jakob’s Law

Summary: Users prefer your site to work the same way as all the other sites they already know. Familiar design patterns increase usability by leveraging users’ prior experiences.

Example: Similar navigation patterns across social media platforms like Facebook, Twitter, and LinkedIn, making it easy for users to navigate new sites.

Actionable Advice:

- Adhere to established design conventions and patterns that users are familiar with.

- Ensure consistency in navigation and layout to prevent confusion.

- Conduct usability testing to confirm that the design meets users' expectations.

7. Law of Common Region

Summary: Elements within the same region are perceived as grouped together. Using visual boundaries to group elements can improve the organization and clarity of the interface.

Example: Grouping of related products on e-commerce sites using borders and background colors.

Actionable Advice:

- Use borders, backgrounds, and visual boundaries to group related items.

- Ensure that items within the same region are related and logically grouped.

- Avoid overlapping regions to prevent confusion and maintain clarity.

8. Law of Proximity

Summary: Objects that are close to each other are perceived as related. Proximity can be used to organize information and create visual associations.

Example: Clustering of buttons in a toolbar to indicate they perform related functions.

Actionable Advice:

- Place related items close together to indicate their relationship.

- Use spacing to create visual groups and separate unrelated items.

- Ensure that the layout is clear and items are logically grouped.

9. Law of Prägnanz

Summary: People will perceive and interpret ambiguous or complex images as the simplest form(s) possible. Designs should be made simple and clear to facilitate user understanding.

Example: Simplified logos like Nike’s swoosh, which are easy to recognize and remember.

Actionable Advice:

- Design for clarity and simplicity, avoiding unnecessary complexity.

- Use clear and straightforward visuals to convey information.

- Test designs with users to ensure they are easily understood.

10. Law of Similarity

Summary: Items that look similar are perceived as part of the same group. Visual similarities can be used to create associations and improve the organization of the interface.

Example: Consistent styling of buttons across a website to indicate they perform similar functions.

Actionable Advice:

- Use similar colors, shapes, or sizes for related items to visually group them.

- Differentiate between dissimilar items to reduce confusion.

- Apply consistent styling for grouped elements to reinforce their relationship.

11. Law of Uniform Connectedness

Summary: Elements connected by uniform visual properties are perceived as being more related than elements not connected. Visual connections can be used to indicate relationships between elements.

Example: Connected form fields with a shared background to indicate they belong to the same form.

Actionable Advice:

- Use lines, colors, and shapes to connect related elements.

- Ensure connections are clear and not ambiguous.

- Use consistent visual connections to maintain clarity and organization.

12. Miller’s Law

Summary: People can hold about seven items in their working memory. Chunking information into smaller groups can help users process and remember it more effectively.

Example: Phone numbers broken into chunks (e.g., 123-456-7890) to make them easier to remember.

Actionable Advice:

- Break information into smaller chunks or groups.

- Limit the amount of information presented at once.

- Use short-term memory-friendly design patterns to facilitate processing and recall.

13. Occam’s Razor

Summary: Among competing hypotheses, the one with the fewest assumptions should be selected. Simplicity leads to better usability and fewer errors.

Example: Minimalist web design that eliminates unnecessary elements and focuses on core functionality.

Actionable Advice:

- Remove unnecessary complexity and focus on simplicity and clarity.

- Streamline user interactions to reduce cognitive load.

- Continuously evaluate and refine designs to ensure simplicity.

14. Paradox of the Active User

Summary: Users often prefer to start using a system immediately rather than spend time learning about it. Intuitive interfaces reduce the need for extensive training.

Example: Intuitive mobile app interfaces that allow users to perform tasks without needing a manual.

Actionable Advice:

- Make interfaces intuitive and self-explanatory to facilitate immediate use.

- Provide in-context help and tooltips to assist users as needed.

- Design for minimal training and maximize usability.

15. Pareto Principle

Summary: 80% of the effects come from 20% of the causes. Focusing on the most impactful elements can maximize user satisfaction and efficiency.

Example: Focusing on key features that users value most in a software application.

Actionable Advice:

- Focus on the most impactful elements of the design.

- Prioritize features that provide the greatest value to users.

- Continuously assess and refine based on user feedback to ensure focus on key areas.

16. Parkinson’s Law

Summary: Work expands to fill the time available for its completion. Setting clear deadlines can improve efficiency and productivity.

Example: Time-boxed project management to ensure tasks are completed within set time frames.

Actionable Advice:

- Set clear, concise deadlines to ensure tasks are completed efficiently.

- Manage time effectively to prevent work from expanding unnecessarily.

- Avoid unnecessary delays and inefficiencies by maintaining a focus on deadlines.

17. Peak-End Rule

Summary: People judge an experience based mainly on how they felt at its peak and its end. Designing for memorable moments can enhance overall satisfaction.

Example: Memorable check-out process in e-commerce that leaves a lasting positive impression.

Actionable Advice:

- Design key moments in the user experience to be particularly positive and memorable.

- Ensure a smooth, satisfying conclusion to interactions.

- Optimize for strong positive peaks and endings to enhance overall satisfaction.

18. Postel’s Law

Summary: Be conservative in what you do, be liberal in what you accept from others. Robust and flexible systems handle user input gracefully.

Example: Robust form validation that accepts various input formats and corrects errors.

Actionable Advice:

- Create robust and flexible systems that handle user input gracefully.

- Ensure systems are tolerant of different types of input to prevent errors.

- Maintain a focus on flexibility and robustness in design.