UX Design Tools: About Card Sorting and Tree Testing

CX & UX Content Collection

There are several interesting UX Design tools out in the market.

The ones we are paying attention to in this article are:

  • Online Card Sorting
  • Tree Testing (a.k.a. Reverse Card Sorting)

Other interesting UX Design Tools are:

A combination of UX design tools can be used to improve your overall user experience and your company’s conversions and bottom line.

Let´s have a look at the ‘how-to’ and benefits of using Online Card Sorting and Tree Testing solutions.

What is Online Card Sorting?

Card Sort

Thanks to technology, Card Sorting can also be conducted remotely, online, and using large samples of participants so you can also obtain statistical significance.

During an Online Card Sorting exercise, a participant is presented with words or phrases (items) and is asked to sort those items into categories (see image).

“Card Sorting is a technique used to help define, structure, or improve the taxonomy and menu structure of a product or website.”

The categories can be defined by the participant (this is called ‘open card sort’) or predefined by the researcher (‘closed card sort’). Most importantly, the Card Sorting methodology gives insight as to how users organise and make sense of information. Card Sorting is most commonly used to inform the information architecture of a product and performed as a stage of the design or redesign process.

Why is Card Sorting an interesting method for UX Pros?


A Card Sorting study can be an invaluable resource to any UX or IA team.

With a well-designed Card Sort, data is used to generate a diagram (dendrogram, see image) that groups items into clusters based on their relationships.

These clusters can be used as a basis for improving the structure of the website.

Quick Tip: The number of clusters, or groups, is often determined by the constraints of the product or website being analysed. For example, if there are 5 top-level navigation categories in a design, 5 clusters will provide 5 groupings of items.

Additionally, an online Card Sorting study can:

  • Help improve an existing site structure or define a new one.
  • Give insight on how to organise and categorise site information.
  • Be created quickly: since it doesn’t require moderation, it is easy to collect data from 50+ participants, while lab based studies are normally limited by cost and time.
  • Save money: online card sorts are much more cost-effective than lab testing. There is no need for lab space, research moderation, or compensating participants for travel.

Quick Tip: The scale from 0 to 1 on the dendrogram represents the linkage distance. A distance of 0 means all participants grouped the items together. The greatest distance, 1, means that no participants grouped the items together.

How does Online Card Sorting work?

  1. Figure out how many users you would like to test.
  2. Quick Tip: Run tests with 50 participants per card sort. 50 participants will allow you the flexibility to exclude participants while maintaining reliable results.

  3. Create your study in your respective online Card Sort tool by including all items that you want your participants to categorise.
  4. Quick Tip: Use no more than 50 items per card sort. When you exceed 50 items you risk burning out the participants and damaging the validity of the data.

  5. Determine whether an open or closed card sort is right for your study.
  6. Quick Tip: An open card sort, where the participant defines their own category names, is used for developing category names and information structure. A closed card sort, where the researcher defines the categories, is used to examine a new or existing navigation structure.

  7. Invite participants.

  8. Launch your study and collect the data.

What is Tree Testing?

Tree Test

This technique closely matches the navigational experience a visitor would have on your site. As you may have already guessed, it is a great compliment to Card Sorting.

A large website is typically organised into a hierarchy (a “tree”) of topics and subtopics. Tree testing provides a way to measure how well users can find items in this hierarchy.

“Tree Testing is a usability technique for evaluating the findability, labeling and organisation of the structure of a website.”

Why is Tree Testing a great research method?

Results Tree Test

A Tree Testing study can can do a lot more than just visually test your site’s navigation. With this type of study, you can:

  • Detect navigational issues early on prior to building a prototype or dynamic site.
  • Analyse first and all attempts where participants had trouble navigating before your site goes live.
  • Create a tree test in under 10 minutes.
  • Like Online Card Sorting, Tree Testing doesn’t require moderation, allowing you to increase your sample size to however many you want.

How does Tree Testing work?

To setup a Tree Test in your online tool, follow these steps:

  1. Organise and create your item hierarchy list, e.g. “products”, “electronics”, “cameras” etc.
  2. Quick Tip: Keep the number of items in your list to under 1000 items to prevent the user abandoning the task prematurely.

  3. Create a task by asking participants to locate a particular product using only the list of items.
  4. Quick Tip:Consider removing “help” and “contact us” topics from your tree test. Guide participants to work with your navigation structure.

  5. Configure options based on your tree testing tool.

  6. Launch your study and collect results.
  7. Quick Tip: Tree Testing results should show first and all attempts which means you will be able to see how successful a real user on your site would be.


¿Son usables los supermercados online? Un estudio de Tree Testing

9 supermercados, 3 países: Nuestros investigadores UX hicieron un estudio de Tree Testing con 180 usuarios de España,, Reino Unido y Alemania.

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