[abugher]

Tangent:

I think you should really have someone who hasn't seen the app test with the blindfold.

Is that double blind, or just single blind plus literally blind?

[fludlight]

In a medical context, double blind means neither the patient or the doctor knows if the patient is receiving the drug being tested or a placebo.

I'm not sure how that would work for software, but it sounds like a much larger experiment than is currently customary.