The best times for conducting tree testing are at several key stages in the product development process to maximize its effectiveness:

• At the beginning of a redesign project: Tree testing at this stage provides clear insights into the existing structure’s performance, helping you identify problem areas. Unlike traditional usability tests, tree testing focuses solely on the IA and helps demonstrate return on investment (ROI) by showing improvements in navigation.
• After a card-sorting study: Card sorting generates ideas about how users group content but often results in multiple possible IA structures. Tree testing helps validate and refine these structures, ensuring the chosen hierarchy works well for users.
• Before generating content or layouts: Tree testing allows you to test different IA options without investing in design, coding, or content development.