Tree testing
Tree testing is a usability technique for evaluating the findability of topics in a website.
A large website is typically organized 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.
Unlike traditional usability testing, tree testing is not done on the website itself; instead, a simplified text version of the site structure is used. This ensures that only the structure is being evaluated, removing the effects of other factors such as visual design.
In a typical tree test:
- The participant is given a "find it" task (e.g. "Look for brown belts under $25").
- They are shown a text list of the top-level topics of the website.
- They choose a heading, and are then shown a list of subtopics.
- They continue choosing (moving down through the tree) - drilling down, backtracking if necessary – until they find a topic that satisfies the task (or until they give up).
- The participant does several tasks in this manner, starting each task back at the top of the tree.
- Once several participants have completed the test, the results are analyzed for each task.
The analysis typically tries to answer these questions:
- Could users successfully find particular items in the tree?
- Could they find those items directly, without having to backtrack?
- If they couldn't find items, where did they go astray?
- Could they choose between topics quickly, without having to think too much?
- Overall, which parts of the tree worked well, and which fell down?
Also known as reverse card sorting or card-based classification[1], tree testing was originally done on paper (typically using index cards), but can now also be done using specialized software.
References
- ^ Donna Spencer (April 2003). "Card-Based Classification Evaluation".