What is card sorting in UX design?

Card sorting is a user experience (UX) research method in which participants group cards with labels written on them in different ways. This reveals the users’ mental maps and helps in the formation of information architecture.

For example, if you are designing an e-commerce website, you might want to know how the users will organize products under different categories. Card sorting can be helpful here as the participants can be asked to organize products into categories.

How to conduct a card sort

The process to conduct a card sort is straightforward. It is described below:

1. Choose a set of main topics - the main topics are the main contents of the interface. Each topic is to be written on a separate card. We should avoid the same terms in different topics as people tend to group them.

2. Ask the participants to organize the cards into groups - the cards are shuffled and given to the participants. The participants organize the cards into groups that they think belong together. There is no fixed size or number of groups to aim for, and the participants can have as many groups and of different sizes. Moreover, the participants can choose to leave out any cards if they wish and can shift cards after assigning them to a group if they wish to before this stage of the activity ends.

3. Naming the groups - after the participants have grouped the cards, they are asked to name the groups. The labels do not have to be very effective, but they reveal the users’ mental model of topic space.

4. Debriefing participants - asking the users the rationale behind the groups they created earlier. Other questions can be if the users found it difficult to group any card or felt a card belonged to multiple groups.

5. Restructure group sizes - after the initial grouping is done, the users can be asked to create subgroups or make larger groups from the initial groups.

6. Repeat - repeat the process with 15 to 20 participants so you observe repetitive patterns that can be generalized.

7. Analyze - see common patterns and what categories are mostly being created, and what are left out. This will dictate the organization of the site.

Types of card sorting

1. Open vs. closed card sorting

• Open card sort - participants are allowed to give whatever names they wish to give the groups they have created.
• Closed card sort - participants are asked to organize cards in predefined categories. It evaluates how well an existing category supports the content.

2. Moderated vs. unmoderated card sorting

• Moderated card sort - the process described above. A great opportunity to gain more insights by asking more questions from the users where needed
• Unmoderated card sort - the process where users organize cards independently (usually through an online tool) without any interaction with the facilitator. A good and cheap supplement to moderated card sort in case of large user groups

3. Paper vs. digital card sorting

• Paper card sort - involves topics written on index cards. This involves no learning curve for users, so no additional burden on them
• Digital card sort - involves the usage of web-based tools to drag and sort cards. Technological issues can hinder the process.

Advantages and disadvantages of card sorting

Advantages

1. Cheap to conduct as no costly equipment is required.
2. Quick to conduct as no extensive prior training is required, and the process itself is not time-consuming.
3. Easy to conduct as the process is easy and does not require complex steps.
4. Established as this has been used for a considerable amount of time and proven useful.
5. Cheap as it does not require any expensive equipment.
6. Insightful as it provides useful information about the users’ mental maps.

Disadvantages

1. The card labels lack context as they are usually very brief.
2. Varied results as people can form totally different mental maps, all equally valid.
3. Time-consuming data analysis, as after conducting the activity, analyzing the arrangement done by every user and understanding it is time-consuming.
4. The insights lack depth at times as there is only the information about the arrangement done by participants and not sufficient rationale behind it unless the participants give a very detailed rationale.

Conclusion

Card sort is a quick and useful method of UX research that helps reveal users’ mental maps and provides important insights regarding the website’s information architecture.