Card sorting is a tool in user research understand the information architecture, how content and information can be organized to best respond to user needs and behaviors. In inviting a user to participate you start to understand how they see and approach the content. Ultimately card sorting is used to help ensure information can be found easily and intuitively. It is also a tool to give us insight into thought processes or mental models.
The Nielsen Norman Group explains how card sorting works through a tea time example of organizing pastries and treats. Consider what you would expect and what you're presented with different items – how would you divide them? [1:58 min]
Types of card sorting
Card sorting can be closed, open, or hybrid. In closed card sorting the cards are already filled out with categories or a description of the subject (for instance, the navigation and content already on your website). In an open card sort, participants are presented with blank cards and undefined categories, and are asked to come up with a system of organization based on a scenario. In hybrid card sorting, some of the cards and categories are provided, but the participant can also add to them.
The benefit of card sorting is that it is low cost and you don't need more than pen and paper (or stickynotes) to complete it. There are also digital tools that can be used to conduct card sorts, which are particularly useful when you're constrained by time or your participants aren't local.
OptimalSort is an online card sorting tool. Their video gives a good overview of how card sorting can benefit something like an e-commerce shop. [2:02 min]
Card sorting can be done by individual participants but sometimes a group dynamic is interesting because you start to hear more mindsets articulated as they talk through the organization together. Of course you want to be aware of any participants who just nod and smile for the sake of finishing the exercise.
Once a card sort is complete you may want to ask the participant which cards were the hardest to organize, or ask them to explain a few of their grouping decisions in order to continue to gain insights.
Information Architect Donna Spencer [16:32] talks about the importance of card sorting. This video is a bit long, but you can start to see the way digital card sorting tools like Optimal Workshop can be used to make your life easier.
Once a card sort is complete you'll end up with different piles of cards. In a closed card sort the titles will already exist. In an open card sort have your participants assign a title, name or category to each grouping.
As with affinity diagrams (see the course Conduct Design Research & Ethnography) one way of analyzing data is through spreadsheets (this link includes a template). Just remember, spreadsheets don't always have all the answers. One of the benefits of using online card sorting tools tools like OptimalWorkshop is that the program helps analyze the data collected. Another approach is to test out ideas with in person card sorts before conducting an online card sort with a larger test group.
Sensemaking created a fake product to explain their approach to card sorting. [3:28 min]