Card Sorting Basics: Efficient Information Architecture for Beginners

Did you know that strawberries aren't actually berries, but nuts? Or that tomatoes are botanically fruits, even though we often treat them as vegetables? But would you actually categorize them that way? Or are strawberries just strawberries to you, and you don't care what would be botanically correct? And how do the rest of your users see it? This is exactly where card sorting comes in!

In this article, we take a closer look at card sorting, explain the different types of this method, and show why it's an indispensable tool in the UX design process. Whether you're just getting started with UX design or want to deepen your existing knowledge – this guide gives you a comprehensive introduction to the world of card sorting.

What Is Card Sorting?

Card sorting is a proven method in user experience (UX) design used to improve the structure and usability of websites and applications. Users sort various terms or pieces of content (cards) into categories that make sense to them. This process helps designers gain a deeper understanding of how users group and structure information.

The Basic Concept

In card sorting, participants receive a set of cards with terms or content on them, which they're asked to sort into groups that feel logical to them. There are two main approaches:

Physical card sorting: Participants receive physical cards that they arrange on a table or another surface. Digital card sorting: Participants use dedicated online tools to sort the cards.

Purpose and Benefits

The main purpose of card sorting is to design or improve the information architecture of a website or application. Here are some specific benefits:

Improved usability: By understanding how users group information, you can design a website's or app's navigation and structure to be more intuitive and user-friendly.
User-centered design: Card sorting brings the users' perspective directly into the design process, resulting in a structure that matches their expectations and mental models.
Efficient problem detection: By involving users in the sorting process, potential problems in the information architecture can be spotted and fixed early on.

Types of Card Sorting

Card sorting is a method in which users sort terms or content into categories. There are two main types, each with its own advantages: open and closed card sorting.

In open card sorting, participants receive cards with various terms or content and are asked to sort them into groups that make sense to them. They create and name their own categories. This method offers valuable insight into how users think, because it shows how people naturally structure information. It's especially useful when you want to develop an entirely new information architecture. Since participants aren't constrained by predefined categories, they can form groups creatively and flexibly, which leads to a wide variety of different and sometimes surprising groupings.

In closed card sorting, on the other hand, participants are given the cards along with predefined categories. Their task is to sort the cards into these given categories. This method delivers more structured and consistent results that are easier to analyze. Closed card sorting is particularly well suited for reviewing and fine-tuning a structure that has already been developed. It lets designers check whether the predefined categories make sense to users and make adjustments if needed.

Besides these two main methods, there's also reverse card sorting, or tree testing, in which users navigate through an existing structure to test how effective it is. We'll cover this in more detail in another article.

By using these methods, UX designers can make sure the structure of their websites and applications meets users' expectations and needs. This improves usability and makes the experience more intuitive.

Why Is Card Sorting Important?

Card sorting plays a crucial role in the UX design process because it helps optimize the structure and usability of websites and applications. But why exactly is this method so important?

First, card sorting significantly improves usability. By understanding how users group and structure information, you can develop a navigation structure that's intuitive and easy to understand. As a result, users find what they're looking for faster and have a more pleasant experience. A well-structured website or application reduces frustration and increases user satisfaction, which ultimately leads to longer time on site and stronger user retention.

Second, card sorting promotes user-centered design. This method brings the users' perspective directly into the design process. Instead of relying on assumptions about how the information architecture should be designed, card sorting gives you concrete data and insights from the point of view of actual users. This ensures that the website's or application's structure matches users' expectations and mental models, which increases both effectiveness and efficiency of use.

Third, card sorting makes it possible to identify problems in the information architecture early. By involving users in the sorting process, potential difficulties and misunderstandings in the categorization can be spotted and fixed early on. This saves time and resources, since problems don't have to be fixed after the website or application has launched.

Using card sorting makes the structure of digital products clearer and more user-friendly. UX designers benefit from deep insight into how users think, which allows them to build products that are intuitive to use and deliver a positive user experience.

How Does Card Sorting Work?

Card sorting is a practical method that can be carried out in just a few steps. Here's how to successfully plan and run a card sorting project from start to finish.

Preparation

The first step in running a card sort is preparation. Start by clearly defining your project's goals. Do you want to develop a new information architecture or review an existing one?

Then decide whether you want to use open or closed card sorting. If you already have a hierarchy in place and the goal is to sort the terms into that structure, closed card sorting is the right fit. If, on the other hand, you want to develop an entirely new structure, open card sorting is more revealing because it exposes how users think.

Create a list of terms or content items to be sorted. These terms should be representative of the content of your website or application.

Recruiting Participants

Choosing the right participants is crucial to the success of your card sort. Select a representative group from your target audience to make sure the results are relevant and meaningful. You should plan for at least five participants, ideally between 10 and 15. If your budget and resources allow, more participants are of course better, since this makes the results more reliable.

Running the Session

There are two main ways to run a card sort: physical and digital.

Physical card sorting: Participants receive physical cards that they arrange on a table or another surface. This method is especially useful when you have direct contact with participants and want to observe their reactions and thought processes. It helps if participants use the “think-aloud” method to verbalize their thoughts while sorting.
Digital card sorting: Participants use online tools to sort the cards. This makes it easy to run sessions even with participants in different locations. Popular tools for digital card sorting include OptimalSort, xSort, and UserZoom. Alternatively, you can use cheaper tools like Miro or FigJam, although they don't offer built-in analysis features. Here, too, the “think-aloud” method should be used to gain deeper insight into how users think.

Analysis

Once the card sort is done, it's time to analyze the results. Collect the data and look for patterns and commonalities in the groupings. These patterns reveal how users structure information and which categories make sense to them. Analysis tools and software can help you visualize and interpret the data.

Finally, you should derive concrete recommendations from the results. These recommendations help you make well-founded decisions about the design of the information architecture and adapt the structure of your website or application to users' needs as closely as possible.

Conclusion

Card sorting is a valuable UX design method that helps optimize the structure and usability of websites and applications. By involving users in the process of categorizing content, you gain deeper insight into how they think and can design the information architecture accordingly.

By deciding whether to use open or closed card sorting and carefully selecting participants, you ensure that the results are representative and meaningful. Sessions can be run either physically or digitally, using digital tools like OptimalSort, xSort, and UserZoom or more affordable alternatives like Miro or FigJam.

A thorough analysis of the sorted cards delivers valuable insights that should lead to concrete recommendations. These recommendations help adapt the structure so that it meets users' expectations and needs.

This content was created with the support of OpenAI's ChatGPT-4 and DALL·E, as well as Midjourney and DeepL. However, the majority of the editorial work was done by our team to ensure authenticity and expertise.