I’m going to conduct a tree test for retail store (womens clothing, bedding, etc. I’m building out the tree test in Optimal Sort. Do I include everything in the tree that looks like navigation on the site or everything that probably IS navigation in the actual site?
For example: Do I include Sale, View All, Specialty Sizes, Featured: Seasonal Lookbooks, etc?
It’s really hard to answer this question correctly without knowing the site. Have you read this piece from NNGroup.com? It may help give you some guidance.
##Defining the Tree
Your tree should be a complete list of all your main content categories, and all their subcategories. Even if you are interested in testing only a specific section of the tree, excluding the other sections is risky because it assumes that users will know which section to go to. For example, if your website had both a Products and a Services category, and you chose to test only the Products tree, you would miss out on finding whether your audience understands the difference between these two categories.
Depending on what part of the hierarchy you are most interested in, your tree may need to be 3, 4, or even 5 levels deep. Include the full depth down to the lowest level of subcategories you want to test. Each subcategory should provide the full list of all the options in that area in order to elicit realistic behavior from users. Users often evaluate link labels by comparing them with nearby alternatives. For example, users interested in history might be tempted to try a category labeled Culture — but not if there was also an option for History Resources.