How do you a double blind sutdy on smartphones? It seems to me that the group that would get smartphone would understand they’re the smartphone group, and the one without would know they don’t have one.
I didn't claim the participants wouldn't know whether they own a phone - obviously they would. I said they wouldn’t know they’re in a study whose purpose is to correlate smartphone use with academic performance.
That's perfectly compatible with a double-blind setup:
* the *students* just think they’re taking standardized tests, not that the effects of their smartphone habits are being monitored;
* the *graders* don’t know whose tests belong to whom.
That’s about as "double blind" as social-science research gets. The commenter I replied to latched onto the literal impossibility of hiding the phone itself, not the intentional design of the experiment.
