What is tree testing?
Tree testing is a usability technique that can help you evaluate the findability of topics on a website. You may have also heard this method described as ‘reverse card sorting’, or possibly ‘card-based classification’.
Tree tests are run on text-based versions of websites, without the influence of navigation aids or design elements, similar to a sitemap. By stripping away everything but the labels and how they’re organized, you can work out just how effective your website structure is at enabling people to find what they need. If test participants consistently struggle to locate specific items, you’ll know there are issues with your structure.
So what do we mean by the “tree”? Well, the tree basically refers to the structure of your website, represented as a list of headings. For example, a tree for a gardening website could be: “Indoor plants>Flowers>Orchids”.
The other aspect of the tree test is the task. When someone arrives on your website, they’re almost certainly trying to find a specific piece of information. Using the example of our gardening website, this could be information about the best time of year to plant apple trees (hint: it’s early Spring).
When running a tree test, we simulate the behavior of using a website by giving users tasks. Tasks should be based on actions that users commonly perform on your website, like navigating to a signup page or trying to find a particular page. These tasks are framed through questions like: “Where would you look for information about the best time of year to plant apple trees?”. We then observe how users go about looking for the answer. Remote usability testing tools such as Treejack can be helpful for logging every step and misstep, automatically helping you discover where people are getting lost.
Where does search fit in?
When trying to design a website’s navigation, it’s all too easy to just throw in the towel and leave everything up to a search function. But this is often a mistake. While a good search engine should be a priority, it’s important to account for browsing as a primary method of seeking out information or completing a task. When people land on a website, they’ll typically try and find what they’re looking for using the navigation as opposed to the search.
Here are 2 resources that break down why you need a well-organized website:
- Promising navigation = Higher likelihood of browsing – Alan McFarlan explains that visitors are more likely to start their use of a website with browsing if the navigation seems clear and offers a number of useful choices.
- Search is not enough: synergy between navigation and search – Raluca Budiu explains that prioritizing search over navigation can lead to a number of issues.
When you should use tree testing
As with card sorting, it’s a good idea to do a tree test early in the research phase. If you have an existing website, this is a good time to establish a base of your existing site structure. The results you gather here can help to highlight any issues with your site structure and provide data to compare any improvements against.
If you’re starting from scratch with a new website, you can run tree tests on different versions of your proposed site structure and then compare the results to determine which makes the most sense to your users.
Online and offline tree testing
Pioneered by Donna Spencer, tree testing was originally done on paper using index cards. Now, it’s almost exclusively performed using online tools like Treejack. Using software for tree testing certainly has its advantages, like being able to conduct unmoderated testing and having the tool conduct your analysis for you.
Online tree testing also has one other major advantage: the ability to gather quantitative data. With in-person, manual tree testing, the results you get are more likely to be qualitative simply because it can be difficult and expensive to get participants to come along to an in-person test. With an online tool, you can create the test and send the link out to as many people as you like.
Limitations of tree testing
Tree testing may be one of the best ways to evaluate the findability of topics on a website, but what happens if you’re building a new website and aren’t sure how people group information in the first place? The answer is card sorting.
Card sorting is the sister method of tree testing, and the 2 techniques are best used together. In a card sort, you task participants with sorting cards containing different words or phrases into groups. For example, you may want to find out how users group topics for a gardening website, so you’d present them with a number of cards containing different gardening terms. Once you’ve had several people complete this test, you’ll be able to identify grouping patterns to learn how your users think.
Use both card sorting and tree testing during the research phase of your project to learn as much as you can about how users group your content and navigate through it.
How to run a tree test with Treejack
Treejack is our tree testing tool and is designed to make it easy to test your information architecture.
Running a tree test isn’t actually that difficult, especially if you’re using the right tool. We’ve put together a comprehensive Tree testing 101 guide that covers everything you need to know about running a tree test with Treejack. You’ll also learn how to set useful objectives, how to build your tree, write your tasks, recruit participants and measure results.