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The big advantage of using online testing tools is that once you we launch a study, it runs by itself; people can participate any time (and any place) they want, and you we don’t have to be there to moderate the session.
The flip side of this, of course, is that you we can’t ask remote participants why they made certain choices or what specifically confused them in a certain task.
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Instead of using this type of tool to test a website, you we give them the web address of your the tree test, and you we get back screen recordings of users doing your the study. Because you we can instruct them to "think aloud", youwe'll be able to hear their reasoning (and possible confusion or misunderstanding) as they click through your the tasks.
See this UserTesting.com blog post for an example of how recording remote sessions helped the author understand what needed fixing in their tree test.
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