>> Good afternoon. So just as a reminder for people in the Monday, Wednesday, Friday class to register your i-clickers. There is a link in the upper right hand corner of the I-learn page in order to do that. If you don't have it registered yet that's fine as long as you have it with you. The system just stores the data until you enter your number in there. Anyways, yes?[ Inaudible comment ]>> AA.>> AA?>> Yes. And we'll be doing a question in just a second. I'll go through that in a sec. So where we left off in the last class was in talking about some observational studies. In particular talking about Alfred Kinsey's interviews, and the basic idea was that in these interviews whatKinsey would do is that he would ask people again a couple of hundred questions I believe it was, that concerned pretty much every facet of their sex lives and their sexual histories, and who they wanted to have sex with, how often they had sex. Did they have sex with animals? Just everything that you could possibly imagine he asked about. And so, a couple of -- let's do a couple of clicker questions here. So the first question is straightforward. Would you participate in a study like Kinsey's? And so set your clicker to channel AA. If it's not that's the default setting. If you set it to a different channel -- where -- oh, there's my glasses. You need to change the channel. If you click and holddown the power button it should start to blink and then just press AA. SoI'll give you another little bit longer to get an answer in. Another 10 seconds or so to get an answer in. All right. Let's stop this. And it looks like 80% of the class would participate and one person not even on the same page as everybody else. And Heather 17% of the class would say no. So just hold that in mind for a little bit. So - Let's go to the nextquestion here. So here's another question. This question whoops. Yes, notwhat I want. There we go. This question is can an observational study definitively determine what causes a particular event such as -- it's noteven written properly, such as why there were higher rates of STI's -- geez why am I? This should be why there are higher rates of STI's among people who grew in their pubic hair? Can observational study definitely determine what causes a particular event? I'll give you a few more seconds to get an answer in. So let's see the answers. That's not going to show me here. One sec. And let's see here. So the majority of the class choose B and that's actually the correct answer. So the correct answer is no. So an observational study cannot definitely tell you what the cause of a particular event is. Now - -- the question is why not? Yes?>> Why?>> Oh, sure.>> No, I just had a question.>> Oh, sure.
>> I thought sometimes observational studies can like cigarette smoke causes cancer. Like that's an observational study they can prove.