Michael Gearon

Card sorting

Michael Gearon

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Card sorting is a user research technique to learn about how your users think about content groupings and terminology that informs the information architecture of a site. It is a way to discover the user’s mental model.

If the session is being done in person it usually consists of physical cards which then the participants arrange into groups that make sense to them and describe those groups with a short label. One of the downsides of doing it with physical cards is that it takes more time for the researcher to record the outputs from the session compared to digital.

If held remotely then it is the same process using an online card-sorting application. The downside to online is that there is a learning curve for users to get to know how the software works and perhaps is not as initiative or as interactive as doing it physically.

With the items grouped and label this helps shape the way things are organised by doing it in a way that makes sense to your users.

Why card sort?

Running a card sorting exercise can be one way to set the structure of the website, help with the wording of categories and ultimately help towards improving the way users interact with your website.

Organising items can be done in lots of ways, if you take a group of books, let’s think of the ways you could organise it on a shelf, you could arrange by:

  • colour on the spine
  • alphabetically
  • theme
  • size of the book
  • author
  • year of publication

Types of card sorting exercises

There are three types of card sorting, open, closed and hybrid.

Open card sort

Open card sorting is where you give people a list of filled in cards and then they decide how they are grouped and what those groups are called. This is the technique to use if you need to understand both how people group together items and then what they would call it.

Closed card sort

Closed card sorting is where you give people a list of cards but the groups are already defined. Use this method when you already know the categories but are not sure which items go into which categories.


Hybrid card sorting is when people have the list of cards, a few existing groups but the user can create their own extra groups if they feel like it doesn’t fall in one of the existing groups.

Moderated or unmoderated sessions

You could run a card sorting workshop as either a moderated or an unmoderated session.

Unmoderated the participant organises the content into groups by themself, usually this would be done remotely using an online application. The benefit of unmoderated is that it can be quicker and cheaper as there is no researcher required and sessions can be done in parallel with less recording of information needed. The downside is you don’t have the insights into why the user grouped and labelled the categories the way they have

Moderated is when there is a moderator through the whole session. This allows for the moderator to ask questions in the debrief after they have completed the task and gain that context that would not be possible with the unmoderated session

You could run a mix of moderated and unmoderated sessions to gain both that qualitative and quantitative set of data which gets you some contextual information without taking too much time or money as running all of the sessions as moderated


Before the session if the site already exists you will need to do a content audit gathering the information you want users to sort, this could be collected into a spreadsheet or a document at this point.

Once you have all of the items together you will then need to prioritise which items will need to be sorted in the session. To prioritise you may want to look at your analytics and quantitative data to work out which are the highest value items to sort first

To avoid participants becoming overwhelmed or tired you may want to limit the number of cards to sort per session. A good rule of thumb is somewhere between 30 to 60 cards would be a good a limit to set yourself

If the site is new then you can run an exercise before the card sort to brainstorm and map all of the pages that will exist on the website

The team and stakeholders can benefit from watching card sorting workshops as it helps resolve any disagreements or different ways of thinking and focuses everyone how the users of the service expect something to be arranged

Card sorting is one of the easier workshops to run and be a creative fun task

Once you have discovered and prioritised which cards you need sorting you now need to prepare for the session

Before the session starts

Before the user turns up for the session you will need to arrange the room. The cards should be shuffled on a large table (find the largest table in your organisation!)

If it’s an open card sort then you will need a few blank cards and a pen for the participant to write the categories

Next you will need some way of recording the session, a video recording as well as audio may be helpful to capture if the users moves the card around a few different categories

As well as the recording and the facilitator you may want to see if there is another colleague who can sit in on the session to take notes and observe the session

Refreshments are vital, you want to make your participant feel comfortable so a good jug of water and cups are always useful, especially as you want participants to speak out loud whilst they are organising

During the session

Once the participant is in the room, explain the task and what you expect them to do. Say that you are looking for them to group together the cards and that it is fine to move them around more than once as they go through the task

If they are being recorded just let them know the session is being recorded, what will happen with the recording and who will see the recording and if they do want to be recorded during the session

Assuming it’s a moderated workshop you can help the participant if they struggle but give them time to work through their thinking first and see if they can do it themselves without much intervention. If they do get stuck this is a good sign for your learnings

After the session

Once the user has completed all of the tasks then it’s time to wrap up the session. This is the opportunity to ask any questions and get clarification on why the user sorted the items the way they have. Take as many photos as you need of the output from the session. You may need to take a few zoomed in photos as well as wider shots so you can clearly read what has been written on the cards

Repeat the sessions until you start to see a pattern emerge around how users group the items and name the groups. Somewhere around 15 moderated sessions should start to form patterns as well as differences between sessions. You will run card sorting workshops alongside other workshops to help inform the information architecture

Card sorting is one tool to start gathering data but it shouldn’t be the only source you gain information from


Used with other techniques, card sorting is a well-established way to inform the information architecture of a website. Running this workshop can help the team and stakeholders understand the user’s mental model of how items should be organised rather than making assumptions.

Michael Gearon

Written by

Michael Gearon

Senior Interaction Designer and Co-Author to Tiny CSS Projects