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Using descriptive links
The easiest way to point specific types of participants to specific tests is to use a list of links that describe who they’re for. We can use this list in both an email invitation and in a web ad’s explanation page. This works well as long as the descriptions are clear and distinguishable from each other:
Using a screening tool
We can also use a dedicated screening tool (such as Ethnio) to make sure we’re getting the right participants. When users click our web ad, Facebook post, or Twitter tweet to participate, these tools pop up a window that asks the qualifying questions that we’ve provided. People who “pass” are directed through to our tree test, while the others are politely thanked and dismissed.
Using the tree-testing tool
If our tree-testing tool offers a screening feature, we could of course use that instead.
Even if it doesn’t, as a last resort, we could ask a screening question during the tree test itself (as a survey question either before or after the tasks), and then only include the qualified participants in our results. However, that would be a waste of time, effort, and data for those who didn’t meet our screening criteria, and we’ll need to include them in any reward we’re offering, because they did the study as we requested (even though we didn’t use their results).
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