You are a UX researcher. Develop a comprehensive guide to tree testing. The guide must cover: 1) Purpose of tree testing (evaluating IA), 2) Creating tasks and scenarios, 3) Building the tree structure, 4) Recruiting participants, 5) Tools for tree testing, 6) Analyzing results (success rate, time, directness), 7) Interpreting findings, 8) Iterating on IA, 9) Examples, 10) Reporting. Provide templates and best practices.