The Definitive Guide to Card Sorting

The Definitive Guide to Card Sorting

Last Edited September 11, 2023 by Garenne Bigby in UX

If you’ve ever visited a site that was disorganized or you couldn’t find what you were looking for (even though you know the information is there), you’ll understand how frustrating a bad layout can be. You may even have decided to stop using that site and changed over to a different company with similar services as a result.

If this has happened to you, you understand the importance of categorizing your own site’s content in a manner that makes navigating to the desired pages an easy matter—because you don’t want to lose clients, of course!

But how do you know whether your site’s layout and categorization is as easy for your users to understand as it is for you? After all, you built the site (or at the very least gave your developer/website manager directions in doing so), and therefore know where to find everything, but your target market may have a slightly different way of thinking. And if your users struggle to find your content the way you’ve grouped it, they too may consider moving on to a competitor. This is where card sorting (and card sorting software or sessions) saves the day.

What is Card Sorting?

Card sorting is the practice of giving users the opportunity to show you how they would categorize your content. This information can be invaluable in ensuring that every visitor to your site (or at the very least the majority of them) are able to easily navigate through your pages while searching for specific content that they know—or hope—you’ve posted.

Basically, a card sorting session presents your participants with a list of topics and a list of categories (in some models, your users will be able to decide on what these categories are as well, to add to those you’ve provided or even change the labels to something they understand better or feel is best suited to the content).

Originally, cart sorting sessions involved actual cards that participants would sort into piles, hence the name, but as technology has progressed card sorting software has become readily available, both as installation based tool and online platforms. Physical card sorting sittings still have their merit, but online sorting sessions has the added bonus of analyzing your results for you, making it easier to implement your new-found knowledge.

This practice allows you not only to test your site’s existing layout for usability, but can also help you plan your layout in advance—whether you’re still developing your site or are considering a redesign.


Open Card Sorting

In an Open Card Sorting session, participants are asked not only to group your website’s contents in a way that seems intuitive and convenient for them, but also allows them to label each category. Some card sorting software also allows users to add sub-categories, which we’ll get to in a bit.

An Open Card Sort is the best way to discover how your target market understands content headings and topics, and—in terms of the names they suggest for each category—how they think of these topics as a whole: what goes well with what.

The added bonus of allowing participants to add sub-categories can be hugely advantageous for you, because they give you an indication of how content grouped under a general label can be further categorized to make site navigation even easier. While main category labels can be used for menu names to display on your homepage or a sidebar, sub-category names will give you the ability to turn these menus into a drop-tab.

For example: you may want to put your business’ contact details, terms and conditions, description, and location under one category with a label such as “company”. Selecting this category will then take your site’s visitors to a page with all of this information available under the appropriate headings. While this is perfectly acceptable, it also means that users will have to do a lot of scrolling to find exactly what they’re looking for on the page.

Turning the “company” menu option on your homepage into a drop tab allows you to list each topic individually so that users can easily select the content they want to view and navigate to the appropriate page in one simple move. No need for skimming over pages looking for the information they want, because now each topic is able to have its own page that is easily accessed straight from your home page!

And if your menu bar appears on each page in your site, it also means users will be able to navigate from one page to any other without much difficulty, provided you’ve used categories and subcategories to your advantage.

Closed Card Sorting

In a closed card sorting session, participants are not offered the opportunity to add new categories and subcategories, nor will they be able to suggest changes to the category names provided.

While it may seem less useful at first glance, having a closed card sorting sitting can be advantageous in various ways. For example, you may have already conducted an open card sorting session to determine the best possible labels. You may also find yourself in a position where you’re unable to change the category names because you’re not the site owner, merely the manager or developer, and your seniors want specific titles used.

In either of these cases, conducting a closed card sorting session will help you to gain a better understanding of how your target market perceives these pre-defined headings, so that you can be sure to add content appropriately.

If you need to impose a time limit on your card sorting sessions, a closed card sort will also be advantageous, as it allows participants to focus on the grouping of your topics without the added task (mandatory or optional) of also changing category titles and adding sub-categories. Limiting your participants might seem like a bad idea, but depending on your needs it can not only help you, but help them too.

Hybrid Card Sorting

Hybrid card sorting splits your sessions into two parts, which can be incredibly useful.

  • Part one would be an open sort, allowing you to gather information on what content works well when grouped together and deciding on category names (and discovering whether sub-categories are necessary, and how to implement them).

  • Part two would then be a closed sort, allowing you to put your category labels to the test and decide whether or not they’re easily identifiable for your users.

Deciding on whether to conduct an open or closed sorting can be complicated, as it’s largely up to personal preference and requirements. Hybrid card sorting allows you to conduct a far more thorough investigation, giving you the best of both, and is almost always a preferred method.

Card Sorting Techniques

One on One Card Sorting

As the name implies, one on one card sorting sessions involve only two people—a participant and an invigilator. The invigilator can be either yourself or a member of your team that you’ve assigned the task to, perhaps a user experience expert that you’ve contracted.

This card sorting technique gives your participant the opportunity to think aloud while categorizing your content, and the facilitator will be able to make notes of the participant’s thought process (assuming it’s a face to face session and not remote, i.e. online). These notes can be incredibly useful in understanding why participants sort topics into certain categories and not others, especially in cases where their choices differ from your own and even surprise you.

Gaining such insight can be invaluably useful in deciding which suggested groupings in a collected survey comprised of many individual sessions you’ll give credence to above others, rather than simply relying on the actual categorization results.

Many online platforms (both installation and browser based) have incorporated a commenting section that allows participants completing a session remotely to effectively think out loud in a way that you (or your designated user experience expert) can still access.

Independent Group Sorting

Geared both toward physical card sorting sessions and (even more so than a one on one session) online surveys, independent group sorting allows for you to create a single session that includes several participants at the same time using a single facilitator.

The invigilator will be able to brief the group before the session begins, or post a single brief that can be read by each participant online. In the case of the face to face session, the invigilator will be able to inquire after individual decisions as well as direct questions to the group as a whole.

With online or software based card sorting sessions, you’ll still be able to pose questions, but these will largely be in the form of a one size fits all method: a set list of questions that participants can opt to answer, or an open comment section for them to fill out.

Each participant still works alone, as with the one on one session technique, but conducting an independent group sorting allows you to gather more data in the same amount of time.

Integrated Group Sorting

An integrated group sorting is best suited to sit-down sessions where the facilitator is able to interact with participants in person. This method follows the same principle as the independent group sorting session, but allows participants to work together in a group, discussing categorization choices and reaching a consensus. With a large group, it can be hugely advantageous to split participants into smaller teams of two or more to help ensure that each participant has a say in their group’s resultant choices.

The facilitator will be able to ask questions of each group or pair during the sorting process, as well as addressing the room as a whole, or waiting until the sorting period has concluded before running through each group’s report individually and posing more focused questions. This also allows for further discussions when two groups have provided vastly different suggestions, and can be turned into a second session where you ask the groups to help you turn separate reports into a single, collectively agreed upon result.

One of the most important roles of the invigilator during an integrated group sorting is to monitor the on-going progress in-session to prevent one or two participants in a larger group from dominating the decision making process, and ensure that each participant gets a fair chance to contribute.

You’ll be able to host an integrated group sorting session by either medium: equipping teams with a set of physical cards, or providing a computer for each group to work on using software of your choice.

Of course, there’s no way to conduct a remote online integrated group sorting, but online participants may sit in pairs and decide on categorization. You just won’t be able to monitor this, or even know whether an online session was completed by an individual or a group of people.

Remote Computer-based Sessions

Although we’ve mentioned remote computer-based card sorting sessions as part of the one on one, independent group sorting, and integrated group sorting techniques, it still merits its own section.

Using online card sorting software can be hugely advantageous, as you won’t need to schedule a time and venue where participants can gather. This technique not only negates the necessity of physical cards or providing a workstation for participants to use (either individually or as a group), but allows them to complete the card sorting session at their own pace in the comfort of their homes or offices.

card sorting results example2

With an online card sorting tool, you’ll be able to post a general brief of participants to work with, and once your project is complete you’ll be given a link that you can share via email, social media, and even post on your site. Many of the software modules also include an integrated recruitment platform, which can further negate any necessity for you to go out and find participants.

Another major advantage to conducting remote card sorting sessions is that the software will analyze the results on your behalf and generate a full report for your consideration. In almost all cases, you’ll be able to export these reports for use in long-term monitoring, business presentations, and sales pitches to potential investors. If you so choose, you can even use these reports in a marketing campaign by providing evidence to substantiate a claim that your site is incredibly user friendly.

While most online card sorting tools and software only work for desktops and laptops, the increasing popularity of tablets has introduced an incorporation of features allowing participants to use them instead of their computer. This in turn lets participants take part in card sorting sessions on the go if they so choose.

View the Top 10 Card Sorting Tools for Surveying Information Architecture

Getting Started

Whether you decide to conduct open, closed, or hybrid card sorting, and regardless of how you choose to conduct your session (individual, group, face to face or remote), you’ll still need to prepare your project.

The first step is choosing your material—so deciding on a software to use, or (if you want to use physical cards) the type of paper you use. For actual cards, try find a durable card, as paper and thin cardboard can not only be tacky but also suffer wear and tear with use.

Next, you need to decide on how many topics you want sorted. Most experts recommend no more than 50 to 70, as greater numbers can and will become overwhelming for participants, especially if you’ve imposed a time limit or they only have a small gap during which to complete the session. If your site requires more than 70 topics to be sorted, you should consider breaking it down into separate sessions.

Then there’s the matter of the topics themselves. As far as possible, you should keep these short and to the point, so as to keep the cards easy to read without compromising on the information that needs to be provided. You’ll also want to number them (for yourself, at least) for use in more advanced analysis, so it’s recommended that you use a table or spreadsheet for listing your topics before creating the cards or uploading them onto the software you’ve chosen to use.


So you’ve got your card sorting session ready, but now you need to find participants. This is immeasurably easier with remote sessions, as you’ll be able to share a link to your session online and invite specific users via email if you so wish, and most card sorting tools also provide their own recruitment forums.

Finding participants for a face to face card sorting session is a lot trickier, especially as you’ll want to incorporate existing clients as much as possible. This is somewhat easier if your business has a walk-in sales point, where you can invite clients to participate, but you may want to consider using a gift voucher or similar reward as an incentive to get them involved and ensure they do participate.

While remote card sorting tools will analyze results for you, face to face sessions require stricter invigilation and manual analysis. Therefore, you’ll want to stick to small groups at a time, with generally around fifteen people. If you do decide to use the integrated group sorting method, you would be best off keeping the pairings down to two or three participants.


Whether conducting your session online or in a boardroom, you’ll need to ensure you have a brief for your participants to follow. This will help to explain what is expected and required from them, and reassure them that there are no wrong answers. If there is a time limit for the session, you should also include this in your brief.

For face to face card sorting sessions, you would be best advised to provide some refreshments for your participants as an added gesture of gratitude—after all, they’re providing a service for you!

Results and Reports

In face to face card sorting sessions, it’s always a good idea to have some means of recording the process, either by jotting down notes or (preferably) making a video recording. This allows you to gather data on the decision making process of your participants as they progress.

It’s always a good idea to leave enough time at the end of the session for a quick debriefing, where you or your appointed invigilator can ask questions to find out where participants may have struggled to categorize labels. This information will be an invaluable addition to the actual grouping.

In the case of an online session, you should keep an eye out for software that allows you to add an optimal comment section at the end of the sorting period, giving participants an opportunity to expand on their choices and explain their decision making process. Some tools allow you to develop a short questionnaire with focused questions for your users to answer. When using this feature, always try to include an open comment section in case any of your participants feel the need to give extra feedback.

For face to face card sorting, you’ll need to manually note the sorting order your participants chose, which is where the numbering system mentioned above comes into play. It’s not often practical to simply photograph the categories, so making note of which numbers were grouped together (and under what labels) will allow for quick and thorough data retention.


Face to face card sorting sessions require you to manually analyze your results, and while online tools will do this for you it’s good practice to bear the following points in mind regardless:

  1. Take note of which topics were grouped together the most often, as well as under which categories, as this will give you an overview of where and how to present your content.

  2. Were there any cards that participants struggled to sort? You may want to consider refining these themes and conducting a second session in order to properly present the content on your site.

  3. If you allowed for participants to make changes to your category headings, add new labels, or suggest subcategories, pay special attention to this. If there are any recurring suggestions, you ought to seriously consider making use of the alternatives to your pre-defined labels.

  4. Were any cards put into more than one category? If there are, you’ll definitely need to refer to point number 1 in deciding which category would be best suited to these topics, but you should also consider refining the explanation given on the card and conduct a second session to see if participants are able to reach a better consensus.

  5. Review the comments made by participants, particularly with regards to any other items of interest they may have brought up.

Card sorting is a proven method for improving your site’s information architecture and usability, giving you a better understanding of how your target market thinks when searching for content on your site.

Finding the method, technique, and platform to conduct your card sorting sessions is largely a matter of personal preference, but you should always ensure that you take the results into careful consideration, making sure that you understand their implications before incorporating them in your site.

If there is any doubt, don’t be afraid to restructure your cards and conduct a follow-up session—and consider doing a card sort before making any changes to your layout, as well as once or twice a year to see whether your target market still navigates through your site in the same way.


Garenne Bigby
Author: Garenne BigbyWebsite:
Founder of DYNO Mapper and Former Advisory Committee Representative at the W3C.

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