And there is some nonresponse going on here. He asks 100 people who sent fan emails to fill out the survey, to say whether they love it or not, 97 fill it out, so there were three people who did not fill out the survey. So there is some nonresponse going on that would be a source of bias, but it's not the most concerning. You know, right over here, they're asking us, fill out the most concerning source of bias, and the convenience sampling is definitely the biggest deal here. There were three people who didn't respond, but that's not as big of a deal. Voluntary response sampling, well, he didn't ask people, like in the last example, like, hey, if you can go here and fill it out, I guess there is actually, actually, no, take that back. There is a little bit of voluntary response here, where he goes to these 100 people and he asks them to respond, and so you have the 97 people who choose to respond.