The definitive guide to card sorting for usability testing

Card sorting is a UX research method that helps you present information in a way that meets the end user’s expectations. It’s a cost-effective and straightforward technique that allows you to get valuable feedback from users.

In this article, we’ll take a look at what card sorting is and how it can help you deliver better user experiences to your site’s visitors. We’ll also go over the pros and cons of using card sorting and explain how to conduct a card sort for your design projects.

What is card sorting?

If you’re like most UI/UX designers, you’re probably guilty of structuring content based on what makes sense to the client or their company and not the intended end user. One way to organize content in a way that meets the user’s expectations is through a UX research technique called card sorting.

The concept behind it is pretty simple: test participants group individually labeled cards in a way that makes sense to them.

Looking at the cards helps UI/UX designers better understand how their site’s intended users expect the content to be structured and enables them to create a robust information structure. For example, if you were designing an e-commerce website that sells women’s clothes, you might create labels for products (t-shirts, blouses, pants, skirts, sweatshirts, cardigans, and shorts) and ask participants to organize them into groups.

There are a few different ways these products can be grouped, for instance, based on seasons (t-shirts and shorts for the summer and sweatshirts and cardigans for winter).

However, your test participants might create the following groups:

• Group A: (t-shirts, blouses)
• Group B: (pants, skirts, shorts)
• Group C: (sweatshirts, cardigans)

Seeing how they group the items helps you get insight into the user’s mental model and uncover patterns. You might find that creating menu items for each group based on card sort results gives you a more usable interface than what you originally had in mind. Following our example, you would then create the following menu items: Tops, Bottoms, and Sweaters.

When (and why) you should use card sorting

Card sorting helps you discover the information structure that would deliver the best user experience to your site’s intended users. Here are some scenarios when you should conduct card sorts:

• Designing a new website, online store, or application.
• Adding new functionality or content to your site.
• Restructuring your site’s content.

Card sorting works best for organizing content that’s similar or comparable. For example, you could conduct cart sorts for organizing questions in FAQs sections, classifying products in an online store, or creating a navigation menu from a complex sitemap.

One of the main reasons UI/UX professionals use this research method is that it’s a quick and cost-effective way to organize content based on the end user’s expectations. In addition to this, it helps you uncover patterns and trends regarding your site’s information architecture.

Card sorting: pros and cons

Nearly all research methods have pros and cons. Let’s step through some of the main benefits and drawbacks of conducting card sorts:

Pros

• Easy, low-cost. Card sorting is an easy research technique for both UI/UX designers and test participants. It’s also inexpensive – you only need index cards and markers to get started.
• Efficient. You can conduct multiple cart sorts quickly, which makes it an incredibly efficient way of gathering valuable information and feedback.
• Based on user input. Card sorting gives you input data directly from the intended users, thereby taking the guesswork out of creating a usable interface.

Cons

• Content-centric rather than context-centric. Card sorting only focuses on making it easy for users to find content and doesn’t take into consideration how they will interact with different tasks on your site.
• Analyzing data is time-consuming. Although conducting a card sort is efficient, analyzing the data you gather from it can take a lot of time – especially when test participants have vastly different responses.

How to conduct a card sort

Card sorting helps you understand how users view, categorize, and label content on your website. There are two main methods of conducting card sorts:

• Open Card Sorting: Test participants receive cards labeled with site content without pre-assigned groups. Participants are then asked to group the cards based on what makes sense to them and then label each group.
• Closed Card Sorting: Test participants receive cards labeled with site content and pre-assigned sets of primary groups. Participants are asked to group the cards into these pre-assigned categories. Most of the time this approach is used when you’re adding new functionality to an existing site.

Here, we’ll show you how to conduct a card sort using the open card sorting technique:

Step #1: Select a set of topics to sort

To get started, choose a set of topics or elements that represents the primary content on your site that you’d like to organize.

Ideally, you should include 40 to 80 items in a card sort. Once you’ve decided which elements you’d like to have organized, label the index cards with the topics (one topic per index card).

As a best practice, mark index cards with unique words, so test participants don’t group cards with the same words in their label together solely because they’re labeled that way.

Step #2: Ask participants to organize topics into groups

Shuffle the index cards and hand them over to the test participant. Instruct them to look at the cards and group cards that they think belong together into stacks.

If the participant is unsure about how to categorize a card or doesn’t know what it means, let them know that they can come back to it later when they have sorted the other cards.

In addition to this, it’s crucial to let test participants know that:

• Some stacks of cards will be larger than others.
• They can change their mind as they work. If the person placed a card into Group B at first, they can move it to Group A later on or create an entirely new Group C.

Once the test participant finishes grouping cards, give them a blank set of cards to write down a label for each group they’ve created. Doing so will help you better understand the test participant’s mental model and give you insight into how you should group the elements on your own site.

Step #3: Debrief participants (optional)

Once the card sorting is complete, you can ask test participants to explain why they created the groups they did and the reasoning behind the labels they assigned each group. You might also consider asking them some follow-up questions or ask them to share insight with you.

For example, you might want more information about how easy or how difficult it was to place a particular element into a stack or if they felt any elements belonged to multiple groups. The more information you gather, the better.

Let’s consider an example. Say, your goal is to organize products into categories. Test participants might tell you that several products seemed to belong under multiple categories. This insight might prompt you to create an entirely new category for your website to sort the overlapping products into or come up with better labels.

Step #4: Analyze the data and interpret the results

Once you’ve collected all of the information and user insights, identify common group names and find products that most participants grouped together.

The patterns that emerge from the data you gathered and the insights collected in the debriefing step will help you come up with a grouping system that would deliver the best, most intuitive user experience to your site’s intended audience.

Conclusion

One way to improve your site’s usability is by organizing information in a way that makes it easy for people to find that for which they’re looking. Through card sorting, you can gather data and valuable insight directly from your end users and use it to come up with an information structure that best matches the user’s expectations.

What are some of the methods you use to improve your website’s usability? Let us know by commenting below.