Simplifying UI Navigation with Hick's Law

What is Hick's Law? The Cost of Choice

At its core, Hick's Law (or the Hick-Hyman Law) is a simple but powerful principle: the more choices a person has, the longer it will take them to make a decision. When the number of options becomes overwhelming, users may experience "choice paralysis" and abandon the task altogether.

To get a formal definition and see the underlying formula, let's start with a foundational reading.

The mathematical formula for Hick's Law is:

Where:

• $RT$ is the reaction time.
• $n$ is the number of choices.
• $a$ and $b$ are constants that depend on the context.

The key takeaway from the formula is that the relationship is logarithmic, not linear. This means that while adding a choice to a small set has a noticeable impact, the effect diminishes as the number of choices grows. However, the core principle remains: more choices lead to more cognitive load.

How to Apply Hick's Law in Navigation Design

Knowing the law is one thing; applying it is another. Let's explore three powerful strategies for simplifying menus and guiding users effectively.

1. Grouping and Categorization

Instead of presenting a long, flat list of options, group related items into logical categories. This is the most common and effective application of Hick's Law. It reduces the initial number of choices a user has to consider.

2. Prioritizing Key Actions

Not all navigation items are equally important. Identify the most frequent or critical tasks your users need to perform and give them visual prominence. Relegate less-used options (like "Legal" or "Help") to a secondary menu or a footer.

3. Using Progressive Disclosure

Progressive disclosure is the technique of showing only the necessary information upfront and revealing more complex or advanced options on demand. A dropdown or "mega menu" is a perfect example of this. The user first chooses a broad category, and only then are the specific sub-options revealed.

The article you just read provides excellent real-world examples of these strategies.

To see these principles applied in a complete redesign, the following case study is a great practical walkthrough.

The "before and after" image from the case study powerfully illustrates the impact of applying these strategies.

Applying Hick's Law to Mobile Navigation

The constraints of a small screen make Hick's Law even more critical. A common pattern is the bottom tab bar. Trying to cram too many options here quickly leads to tiny, hard-to-tap targets and a cluttered feel.

This video provides a clear, actionable rule of thumb for mobile navigation.

As the video states, the golden rule is to aim for three to five tabs. This provides quick access to core features without overwhelming the user, perfectly aligning with Hick's Law.

An Important Nuance: When Are Long Menus Okay?

It's tempting to think "fewer choices are always better," but that's an oversimplification. Hick's Law primarily applies when users are trying to decide between unfamiliar or uncategorized options. There's a key exception.

Watch this short video from the Nielsen Norman Group to understand the nuance.

Think of a dropdown menu for selecting your country. You already know the name of your country, and you know the list is alphabetical. You don't decide which country to pick; you locate a known item. In this scenario, you can scan the long list very quickly.

Your Turn: Audit and Redesign a Menu

Now it's time to apply what you've learned. This hands-on exercise will prepare you for a common task in freelance projects: analyzing an existing interface and proposing improvements.

Your Task (25-30 minutes):

1. Select a Subject: Go to a large e-commerce website with a complex navigation system (e.g., Amazon, Etsy, or a large department store site).
2. Capture the "Before": Navigate to the website's main "mega menu" (e.g., hover over "Shop by Department" or a similar primary category). Take a screenshot of the full, expanded menu.
3. Analyze in Figma:
   • Create a new file in Figma and paste your screenshot.
   • Next to the screenshot, add annotations critiquing the menu based on Hick's Law. Ask yourself:
     • How many choices are presented at once?
     • Is it overwhelming? Why or why not?
     • Does it use grouping, prioritization, or progressive disclosure effectively?
     • Are there any long lists that meet the "ordered and known" criteria?
4. Sketch a "Quick Redesign":
   • You don't need to create a pixel-perfect design. Using simple shapes and text boxes, create a wireframe of how you would redesign the menu to better apply Hick's Law.
   • Focus on structure. Would you group certain items differently? Would you create new sub-categories to reduce the initial number of choices? Would you use more white space?
5. Justify Your Changes: Add a few text notes to your redesigned wireframe explaining why you made the changes, explicitly referencing the principles from this lesson (e.g., "I grouped these 8 links into a 'Home Goods' sub-category to reduce the primary choice count from 20 to 13.").

This exercise will solidify your understanding and give you a tangible example of applying psychological principles to solve a real-world design problem.

Conclusion

Today we've unpacked Hick's Law, a cornerstone principle of interaction design. You've moved beyond the simple idea of "less is more" to a more nuanced understanding of how to manage choice and complexity for the user.

Key Takeaways:

• Hick's Law: The time it takes to make a decision increases with the number of choices available. Ignoring this leads to cognitive load and choice paralysis.
• Core Strategies: You can simplify navigation by grouping related items, prioritizing essential actions, and using progressive disclosure to hide complexity.
• The Exception: Long lists are perfectly fine if the items are known to the user and presented in a logical order (like a list of countries), as this changes the task from deciding to locating.
• Mobile Matters: On mobile, limiting primary navigation like tab bars to 3-5 items is a direct and effective application of Hick's Law.

Preview of the Next Lesson:
We've just learned how to reduce the cognitive effort of choosing an action. In the next lesson, we'll focus on reducing the physical effort of executing that action. We'll explore Fitts's Law, which provides a model for designing clickable targets (like buttons and menu items) that are fast and easy to hit.