Hick's Law

It’s Friday night. All you want to do after a long week of work is to watch a movie. You browse through a streaming site, scrolling through comedies, dramas, and thrillers. But with each flick of your thumb, the list grows longer. The seemingly endless catalog overwhelms you as the struggle to find the perfect movie intensifies. Minutes turn into tens of minutes and you are still nowhere close to picking a movie. With all the choices in front of you, the decision-making process becomes a burden and you give up with the movie night idea.

This is Hick’s Law in a nutshell. It describes the psychological phenomenon where the time it takes to make a decision increases in the face of multiple choices.¹ In short, the more options people have, the longer it takes to choose.

It seems that being given the option of 3 movies is more appealing than having to scroll through pages of movies on the streaming site. In this situation, Hick’s Law demonstrates how an abundance of choices can lead to decision fatigue, leaving you stuck in a cycle of indecision and endless scrolling.

User Experience (UX) Design: Design used to create meaningful digital experiences for users. It calls for designers to understand their users’ needs, preferences, and behaviors to produce a product that effectively meets these elements.

Logarithmic: A mathematical concept used to describe a relationship between two variables. We see one variable increase less and less as the corresponding variable continues to increase.

In William Edmund Hick’s 1952 article, “On the rate of gain of information”, he established a relationship between stimuli and reaction time.² Hick’s experiments required participants to respond to a series of lights whenever it lit up on a corresponding key.³ With 10 lamps circling the subject and a corresponding key for each finger placed in front of them, Hick could measure participants’ response time closely. For the first two trials, participants were instructed to respond as accurately as possible, while the final trial had participants respond as quickly as they could. The results highlighted that participants performed poorly when there were too many lights to respond to, regardless of accuracy or speed. The time it took for participants to respond to the light stimuli increased logarithmically with the addition of lights.

Ray Hyman set out to better understand Hick’s findings. By experimenting with lights he arranged in a 6x6 matrix, Hyman determined that reaction time linearly increased with stimuli amount.⁴ In other words, the more stimuli present, the longer the reaction time.

Hick’s Law is based on the assumption that our brains have a limited capacity to process information. When we are met with too many options, our internal information processes become overloaded which may lead to decision fatigue, delays in decision-making, information overload, and indecisiveness altogether.

Since its conception, Hick’s Law has been applied across disciplines, namely psychology, human-computer interaction and UX design. It has become a fundamental guiding principle in the design of user interfaces, aiming to simplify choices and reduce decision-making time for users.

William Edmund Hick—a British psychologist and pioneer in the fields of experimental psychology and ergonomics during the mid-20th century. A founding member of the Experimental Psychology Group, his most well-known contribution was his 1952 paper titled “On the rate of gain of information”.⁵ The effect found in the study went on to be referred to as Hick’s Law.

Ray Hyman—a Professor Emeritus at the University of Oregon and one of the founders of the modern skeptical movement. Hyman’s seminal paper on human choice, reaction time, and information content marked a shift from behavioral psychology to the era of cognitive psychology.⁶ 

Hick’s Law firmly echoes a design principle, popularized in the 1960s, known affectionately as “K.I.S.S.” (“Keep it simple, stupid!”).⁷ By simplifying the number of choices presented to the user, designers can avoid bogging users down in the decision-making process. This increases the likelihood that users complete their desired action and promotes a better user experience overall.

However, reducing users’ choices to enhance decision-making does not mean designers must avoid complexity. The point of Hick’s Law is to try to simplify the choices users need to make rather than to eliminate the need to choose at all.

Although hailed for the insights provided on choice and reaction time, Hick’s Law doesn’t save the universe from encountering poor designs. A major controversy surrounding the law is its application to real-world scenarios and complex decision-making processes.

User Familiarity

Users’ familiarity with an interface may override the predicted effects of Hick’s Law. Because they can make probable expectations or because the compatibility between the choice and the response is highly intuitive, Hick’s Law has the potential of becoming redundant.⁸

Product Purpose

The purpose of the product matters too. If the product is targeted towards a more expert audience, then simplifying the design may defy the product’s ability to perform advanced functions. For example, a DSLR camera has many more functions than your typical smartphone camera because it is catered to users with experience in photography. Following Hick’s Law may limit the power of a product which defeats its purpose.

Users’ Intention

Finally, we need to consider the users’ intentions. Users may face situations when they prefer to maximize their options. For instance, picking a hotel or a restaurant to spend a special occasion at. Being able to view all the options, and compare and shortlist them before making a final selection may aid in users’ decision-making. So, defying Hick’s Law may sometimes be the more optimal design for the best user experience.

Amazon’s Checkout Process (Innovation and Design x Technology and AI)

Amazon’s checkout process separates each stage into its own page. When proceeding through the checkout, customers are first asked to input their shipping address. The next page then requests for their payment information and the final page provides a summary of the shipping and billing details. Each page contains a clear call to action for their customers.

By breaking down the checkout into separate stages, Amazon prevents its customers from being overwhelmed by the volume of information the site is asking for. This helps ensure a smooth checkout process and avoids frustration for their customers, leading to a better user experience.

Learning how to use new apps (Education x People and Organization)

Hick’s Law can also be used to inform how app designers teach users how to use their app for the first time. An example would be the popular language learning app, Duolingo.

When users first open the app, Duolingo guides them through a tutorial that introduces its language learning methodology, user interface, and key learning features. The tutorial is typically interactive, requiring users to perform the call to action before moving on to the next step. By staggering the tutorial into simple steps, users can quickly familiarize themselves with Duolingo’s interface, allowing them to navigate the app confidently.

This form of progressive onboarding helps avoid the impact of Hick’s Law on users. Simplifying the app tutorial into a step-by-step process prevents users from being overwhelmed with new information. It sets them up for success and encourages them to continue using the app.

Choice Overload Bias

Ever wondered why it is trickier to make a choice when we have more options? Choice overload bias contradicts the widespread assumption that more choice means more freedom. It seems that having to choose between numerous options overcomplicates our decision-making processes, making it harder to decide. 

The Paradox of Choice

We hear the phrase “the more, the merrier” in our daily lives. We assume that encountering multiple options makes it more likely that we choose an option we are happy with. As it turns out, having more options requires more effort to choose between which may result in feeling unsatisfactory with your final choice.

1. Yablonski, J. (2022). Hick’s Law. Laws of UX. https://lawsofux.com/hicks-law/
2. Hick, W. E. (1952). On the Rate of Gain of Information. Quarterly Journal of Experimental Psychology, 4(1), 11–26. https://doi.org/10.1080/17470215208416600
3. Inchara Prasad. (2023, June 1). Hick’s Law: The Psychology of Decision Making. Medium. https://medium.com/@incharaprasad27/hicks-law-the-psychology-of-decision-making-11bb52822a18
4. Hyman, R. (1953). Stimulus information as a determinant of reaction time. Journal of Experimental Psychology, 45(3), 188–196. https://doi.org/10.1037/h0056940
5. See 2.
6. Simon Fraser University. (2009, April 8). 2007: Dr. Ray Hyman. Www.youtube.com. https://www.youtube.com/watch?v=vmBZhTH0Imc
7. Soegaard, M. (2019, November 4). Hick’s Law: Making the choice easier for users. The Interaction Design Foundation. https://www.interaction-design.org/literature/article/hick-s-law-making-the-choice-easier-for-users
8. Liu, W., Gori, J., Rioul, O., Beaudouin-Lafon, M., & Guiard, Y. (2020). How Relevant is Hick’s Law for HCI? Proceedings of the 2020 CHI Conference on Human Factors in Computing Systems. https://doi.org/10.1145/3313831.3376878