Ditch the Superficial: The UX Laws that Drive SaaS Performance

1. Pareto's Principle: 80/20

You're probably familiar with Pareto's Principle, also known as the "80/20 rule." Popularized by the Italian economist Vilfredo Pareto, it states that 80% of effects come from 20% of causes. But did you know that this principle also applies to the UX design of your SaaS?

In practice, this means:

• 80% of your users probably only use 20% of your platform's features.
• 20% of your features generate 80% of your added value.

Ignoring this principle can lead to a complex interface overloaded with rarely used features, which detracts from the overall user experience.

How to put Pareto's Principle into practice for my SaaS?

• Identify key features: Analyze your users' behavior with analytics tools and satisfaction surveys. Focus your design and development efforts on the 20% of features that generate the most engagement and value.
• Simplify the interface: Reduce visual and cognitive noise by highlighting key features and relegating secondary options to less prominent locations.
• Test and iterate: Applying Pareto's Principle is an ongoing process. Don't hesitate to test different configurations and adjust your interface based on user feedback and usage data.

By applying the 80/20 principle, you create a clear, intuitive, and value-oriented interface, which improves the adoption of your SaaS, reduces churn rate, and boosts your growth. But simplifying the user interface doesn't mean neglecting its ability to handle the unexpected. That's where Postel's Law comes in.

2. Postel's Law: Anticipate the Unexpected for a Robust UX

Also known as the "robustness principle," Postel's Law, formulated by Jon Postel, states to "be conservative in what you do, be liberal in what you accept from others." Applied to your SaaS UX, this translates to:

• Tolerance for user errors: Your interface should be designed to anticipate and handle input errors, unconventional actions, and unpredictable user behavior. A clear, concise, and informative error message is always preferable to a system crash!
• Compatibility and adaptability: Ensure your SaaS displays and functions correctly across various browsers, devices, and operating systems. Also, consider the variety of internet connections and potential bandwidth limitations.

How to put Postel's Law into practice for my SaaS?

• Validate forms intelligently: Use micro-interactions to indicate errors in real-time and guide the user towards correct input.
• Offer alternative navigation options: Provide breadcrumbs, a history of recent actions, or a powerful search function to help users find their way.
• Test your SaaS compatibility: Conduct tests across different browsers (Chrome, Firefox, Safari, Edge...), operating systems (Windows, macOS, iOS, Android), and screen sizes.

By integrating Postel's Law into your design process, you strengthen the robustness and reliability of your SaaS. Even when faced with unforeseen circumstances, users will feel confident and appreciate the smooth flow of their experience. However, fluidity shouldn't equate to superficiality. As Tesler's Law points out, the apparent simplicity of an interface often hides a tremendous amount of work by designers.

3. Tesler's Law: Simplify to Avoid Scaring Users Away

"Every system has an irreducible amount of complexity. The goal is to make it as simple as possible for the user," stated Larry Tesler, a pioneer in human-computer interaction (HCI). In other words, Tesler's Law reminds us that the simplicity perceived by the user is the result of significant design effort to mask the inherent complexity of the system.

For your SaaS, this means:

• Don't force the user to adapt to the system: The interface should adapt to the user's needs and habits, not the other way around.
• Reduce the number of steps to achieve a goal: The simpler and more intuitive the user journey, the greater the satisfaction and engagement.
• Prioritize clarity and conciseness: Avoid technical jargon and superfluous information that may confuse the user.

How to put Tesler's Law into practice for your SaaS?

• Create intuitive workflows: Break down complex tasks into simple and logical steps.
• Use familiar icons and visual elements: Facilitate understanding and navigation by relying on a universal visual language.
• Test the usability of your interface: Have real users perform specific tasks on your platform and gather their feedback to identify friction points and areas for improvement.

By following the precepts of Tesler's Law, you create a SaaS that is enjoyable to use, easy to learn, and encourages users to return. But simplicity is not enough: efficiency is just as crucial for an optimal user experience. This is where Fitts's Law comes in, establishing a direct link between interface design and the speed of task completion.

4. Fitts's Law: Targeting Speed and Accuracy of Interactions

Formulated by psychologist Paul Fitts in 1954, this principle states that the time it takes to reach a target on the screen depends on its size and distance from the cursor's starting point. In short:

• The larger and closer the target, the easier and faster it is to reach.
• The smaller and farther away the target, the more difficult and time-consuming it is to reach.

Applied to your SaaS UX, Fitts's Law directly influences the placement of interactive elements:

• Action buttons: Call-to-action buttons (Sign up, Try for free, Download...) must be large enough and visible to be easily clickable, especially on mobile devices.
• Navigation: Menus, tabs, and other navigation elements should be placed in strategic and easily accessible locations.
• Spacing: Adequate spacing between interactive elements prevents misclicks and facilitates visual navigation.

How to put Fitts's Law into practice for your SaaS?

• Play with contrast and color to highlight key elements.
• Use sufficiently large clickable areas, especially for frequently used actions.
• Group similar items to facilitate reading and navigation.
• Consider the "hot zones" of the screen, i.e., areas that are naturally easier for the user to access.

By applying Fitts's Law to your SaaS interface, you reduce friction, improve navigation flow, and speed up interactions. Users gain comfort and efficiency, which contributes to a positive overall experience. However, speed should not come at the expense of familiarity. This is where Jakob's Law comes in, emphasizing the importance of relying on established conventions for an intuitive user experience.

5. Jakob's Law: Don't Reinvent the Wheel, Leverage Familiarity

Jakob Nielsen, another leading figure in user experience design, states that "users spend most of their time on other websites." Jakob's Law, or the principle of familiarity, stems from this observation: users prefer to interact with systems that work similarly to what they already know.

In other words, it is crucial that your SaaS:

• Uses standard navigation and interaction conventions: Main menu at the top of the page, clickable logo leading back to the homepage, shopping cart icon at the top right... these conventions, though they may seem trivial, reassure the user and allow for intuitive navigation.
• Employs clear and accessible language: Avoid technical jargon and obscure terms. Favor simple and direct language that your users can easily understand.
• Draws inspiration from best practices in your industry: Observe how your competitors design their interfaces and identify the elements that work well. Draw inspiration from them, while maintaining your brand's unique identity.

How to apply Jakob's Law to your SaaS?

• Conduct a benchmark of your industry: Analyze the most popular SaaS websites and applications, identifying commonalities in navigation, design, and information organization.
• Use standard user interface (UI) components: Buttons, dropdown menus, search fields... favor visual elements that are familiar to users.
• Test the usability of your interface with real users: Observe how they interact with your SaaS and identify friction points related to a lack of familiarity.

By following Jakob's Law, you create a smooth and intuitive user experience. The user can focus on completing their tasks without having to decipher a complex interface or relearn navigation patterns. For a truly intuitive experience, it's not enough for elements to be familiar; the information also needs to be clear, concise, and easily digestible. This is where Miller's Law comes in.

6. Miller's Law: Don't Overload Users' Memory

Psychologist George Miller demonstrated that an individual's short-term memory is limited to around 7 items (plus or minus 2) of information at a time. Applied to UX design, Miller's Law reminds us to present information in a digestible way to avoid cognitively overloading our users.

Concretely, for your SaaS, this means:

• Chunking, or breaking down information: Break down long texts into short paragraphs, use bullet points, group information into tables, and create clear visual hierarchies with headings and subheadings.
• Visual hierarchy: Highlight the most important information using size, color, font, and spacing. Guide the user's eye and facilitate quick understanding.
• Reducing cognitive load: Display only the information strictly necessary at any given time. Hide secondary elements behind drop-down menus, tabs, or modal windows.

How to put Miller's Law into practice for your SaaS?

• Simplify forms: Ask only for essential information and break down long forms into multiple steps.
• Use visual aids: Integrate images, icons, and illustrations to make information more attractive and memorable.
• Structure information logically: Organize content in a clear and consistent order to facilitate reading and comprehension.

By applying Miller's Law, you facilitate the understanding and memorization of information. The user can focus on the essentials and interact with your SaaS more smoothly and efficiently. However, another factor can hinder decision-making and negatively impact the user experience: choice overload. This is precisely what Hick's Law highlights.

7. Hick's Law: Too Much Choice Kills Choice (and Engagement)

Hick's Law, also known as the Hick-Hyman Law, states that the time it takes to make a decision increases proportionally with the number of options available. In other words, the more choices a user faces, the longer it will take them to make a decision, increasing the likelihood of frustration and abandonment.

For your SaaS, this implies:

• Limiting the number of options in menus and navigation bars: Favor a clear and concise information architecture with well-defined categories and a limited number of options per level.
• Simplifying key pages: Identify the main actions you want users to take on each page (e.g., signup, purchase, download) and make them prominent.
• Using "progressive disclosure" techniques: Instead of presenting all information and features at once, reveal them gradually, based on the user's needs and their journey through the platform.
• A SaaS Gamification Strategy can be a powerful tool for guiding users through complex choices, making the experience smoother and more engaging.

How to apply Hick's Law to your SaaS?

• Define a clear visual hierarchy: Use size, color, contrast, and spacing to guide the user and help them quickly identify important elements.
• Segment your users and personalize the experience: Offer pathways and options tailored to the specific needs of each user based on their profile, behavior, and goals.
• Test the effectiveness of your information architecture: Conduct user testing to observe how users navigate your platform and identify friction points related to choice overload.

By applying Hick's Law, you contribute to creating a smoother and more enjoyable user experience. Freed from decision paralysis, users can interact with your SaaS more naturally and achieve their goals faster. Yet, even with an intuitive interface and clear choices, another factor can hinder efficiency and user satisfaction: the tendency to unnecessarily complicate tasks. This is where Parkinson's Law comes in.

8. Parkinson's Law: Time Equals Engagement (and Vice Versa)

"Work expands so as to fill the time available for its completion." This observation by British historian Cyril Northcote Parkinson, which gave rise to Parkinson's Law, invites us to deeply reflect on our time and task management, including in the context of UX design.

Applied to your SaaS, Parkinson's Law means that:

• The more time you give users to complete a task, the more likely they are to perceive it as complex and time-consuming.
• The more steps and options you offer, the more likely the user is to get lost and abandon the process.

How to counter Parkinson's Law in your SaaS?

• Set reasonable (but binding) deadlines: Encourage users to take action by incorporating time limits for certain actions (e.g., completing registration, taking advantage of an offer...).
• Define clear and concise processes: Limit the number of steps required to achieve a goal. Each step should be essential and add value.
• Offer shortcut options: Allow experienced users to save time by providing keyboard shortcuts, import/export options, or advanced features.

By applying Parkinson's Law to your interface, you encourage efficiency and user satisfaction. Users, less prone to procrastination and distraction, achieve their goals faster and remain engaged with your SaaS.

Conclusion

Mastering these fundamental UX laws ensures that every interaction with your SaaS is a positive and engaging experience for your users. By combining the power of Gestalt principles, explored in our previous article, with a thorough understanding of the principles outlined in this guide, you now have all the keys to create an intuitive, high-performing, and addictive interface.

Remember that UX design is an iterative process. Test, measure, adjust, and above all, listen to your users to create a SaaS that perfectly meets their needs and fosters long-term loyalty. And above all, don't develop a B2B SaaS without reading these 4 lessons to learn from B2C apps.

Ready to boost your SaaS UX and maximize its growth potential?

Our team of UX design experts is here to support you. From designing mockups to creating comprehensive design systems, conducting UX audits, and integrating gamification mechanics, we put our expertise to work for your success.

Contact us today for a free consultation and discover how we can help you make your SaaS a benchmark for user experience.