Types of Card Sorts
There are two basic types of card sorts:
- open card sorts
- closed card sorts
Open Card Sorts
For an open card–sort exercise, ask participants to organize navigation items for a Web site or application into categories, as they see fit. Then, ask them to name each category, choosing a label for each category that provides an accurate description of its content. An open card sort is useful when you want to learn how users group content and what terminology or labels they would use for each category.
Closed Card Sorts
For a closed card–sort exercise, ask participants to organize navigation items for a Web site or application into predefined categories. A closed card sort, or reverse card sort, works best when a predefined set of categories already exists. A closed card sort is useful when you want to learn how users would group content into each predefined category.
Combining Card-Sort Techniques
At times, it may be useful to try combining both of these techniques. For example, you might initially conduct an open card sort to identify categories, then conduct a closed card sort to validate the category labels and groupings of items. Recently, I worked on a project on which we took a similar approach.
There are a number of tools on the market that are specifically for card sorting, including xSort, Optimal Sort, and UX Sort. Plus, you can use Microsoft Excel’s pivot tables for card sorting.
xSort is a free card-sorting application for Mac OS that is shown in Figure 1. Its user interface consists of a virtual table top and a set of cards that participants can group. This application supports both open and closed card sorts and provides detailed statistical results, including dendrograms that are based on cluster analysis.
Optimal Sort is an effective Web application for remote card sorting. The free version of the application supports only open card sorting, but the premium version also includes support for closed card sorting. Optimal Sort provides comprehensive results, including a similarity matrix, dendrograms, and a Participant-Centric Analysis (PCA).
UX Sort is a free card-sorting application for Windows. Similar to xSort, the user interface consists of a table top and a set of cards that participants can group. The application supports open card sorting and provides results as dendrograms that are based on cluster analysis.
The versatility of Microsoft Excel allows you to use the application as a simple tool for card sorting. You can conduct both open and closed card sorts using Excel, then analyze the data you’ve gathered from participants by creating a pivot table. More experienced Excel users can use features such as slicers for comprehensive results or PowerPivot for a visual representation of the results.
Physical Versus Digital Card Sorting
The key advantage of physical card sorting is the personal touch of interacting with participants face to face. You can gain a lot of insights into participants’ mental models by observing them during physical card—sort sessions. However, one of the biggest challenges of a physical card sort is data analysis. Conducting a physical card–sorting session is simple, but analysis can be cumbersome and time consuming. However, conducting a physical card sort is useful for a small group of participants with an information space that is not too large—that is, one with less than about 40 items.
Using software is more efficient for analyzing and generating card-sort results. Almost all card-sorting applications use cluster analysis and generate dendrograms. You can use applications for remote card sorting, which lets participants initiate a session at their convenience. However, such applications provide only statistical data and don’t provide any insights into the participants’ mental models. Use these applications when participants are spread across geographies or the number of participants is large.
Usability.gov. “Card Sorting.” Usability.gov, undated. Retrieved January 6, 2017.
Hudson, William. “Card Sorting.” Interaction Design Foundation, undated. Retrieved January 6, 2017.