Tree Testing

What is tree testing?

In a tree test, participants see your navigation structure as a plain, expandable list of labels, the so-called tree. They get tasks such as "Where would you find information on returns?" and click through the levels until they think they have reached the right place.

Since there are no colors, images or layout, you are testing only the structure and the naming of your categories. The method is often described as the counterpart to card sorting: card sorting helps you build a structure, tree testing tells you whether it works.

Why tree testing matters

When people can't find something, the cause is rarely the button style. It is usually the information architecture. Structural problems get expensive once they are baked into design and code. Tree testing shows you early which categories are confusing, where labels overlap and which paths lead people astray. You see how many participants reach the correct destination, whether they get there directly and where they first take a wrong turn.

How to use tree testing in practice

• Include the full tree: Add every relevant level, not just the top navigation.
• Write neutral tasks: Avoid the exact menu labels, otherwise you are only testing word matching.
• Keep it short: Eight to ten tasks per participant is plenty before focus drops.
• Look at first clicks: The first click reveals which category people believe is responsible.
• Compare versions: Run the current and the proposed structure with the same tasks.

Example

An online store for natural skincare files the size guide for accessories under "Service". In the tree test, most participants look for it inside the product category instead. The fix is simple: link the information where people actually expect it.