 This is a double blind experimental setting thing. No, double blind control procedure, OK? So a double blind, a double blind control. Just double blinds, DBs. So I don't know, database, anyway, sorry. Just totally getting off topic here, but that's OK. Because I'm keeping you blind. No, double blind is a way to increase quality of, reduce bias in our observations. So we want to reduce bias in our observation. The best way to do that, one of the best ways to do that is to blind the subjects from the experiment. And then you say, block you. No, so to blind the subjects, you don't let them know what condition they're about to experience. You don't let them know when the condition phase change happened. You literally don't tell them as little as possible, OK? So it blinds them so they can't have a placebo effect go on or they can't hypothesis guess all that fun stuff. Then you also blind the observer. So you don't tell them when the phase change happened either, right? That way they can't do their whole bias EPs, OK? So when they're collecting the data, all they do is counting the behaviors. They don't go, oh, now it's the new condition. So I'll count more behaviors. Double blind keeps everything under wraps in terms of bias. And it is an important procedure that you should try to implement any time you're doing an experiment.