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Main content
Current time:0:00Total duration:4:36
AP.STATS:
DAT‑2 (EU)
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Video transcript

we have some type of study described here I encourage you to pause this video and think about whether this is an observational study it's an experiment or it's a sample study and also think about whether it was conducted well alright now let's do this together a group of doctors was interested in comparing the effectiveness of placebo pills and real pills and treating migraines and placebo pills are pills that look just like the regular pill and from a patient's point of view they don't know which one they're getting and the reason why we do this in studies is because there's something called the placebo effect oftentimes just by taking things something that you think is good for you some medicine that you think might help you it actually does help you and we can think about why the placebo effect happens but this is well documented and so when people are trying to test medicine they want to say well does this have an effect above and beyond the placebo effect and so that's why they are putting them in these - in it that's why they're comparing the real pills to the placebo pills so they randomly assigned a group of 300 patients suffering from migraines into two groups so they have their 300 they have their 300 patients right over here and they're randomly putting them into the placebo group placebo group or the real or the real pill group one group was given a real pill we already ready when we are you read that both groups were told which kind of pill they got that is sketchy because the whole point about a placebo is that you think you got the real thing or you think you might have gotten the real thing and if you're told you got a placebo that tends to undermine the placebo effect if you're just told you're giving a a sugar pill well then the the impact of both no anyway this this is this is that right over there is definitely bad practice so let's let's keep going here before taking the pills in a day afterwards the patients were asked to fill out questionnaires regarding their condition then the doctors analyze the overall changes in questionnaires for each group and compared them all right so first of all what type of study is this well we're taking our groups we are randomly putting them into two different groups you could call the placebo group or maybe the the control group and then you're putting the real pill as your actual experimental group and so this is a classic experiment this is a classic experiment you're trying to establish a causal relationship you want to see whether this real pill actually makes migraines better my migraines better so does it actually do it and it does actually do it better than a placebo and you're randomly putting the people in both groups to try to distribute any confounding variables that there might might be there so this is clearly an experiment now the other options you might say well is this maybe an observational study and remember in an observational study observationally that's more of where you look at a population you look at a group you ask them a bunch of questions often or you make a bunch of observations and you see if there's correlations between two variables so variable one and variable two and you're able to make some type of correlational statement and you're not trying to get at causality and in a sample study a sample study this is just you trying to estimate a parameter for the entire population so a sample study might have been of the entire population what percentage gets migraines and you don't you can't talk to the entire population maybe the entire population is millions of people so you take a sample of say a hundred people and you ask them do you get migraines and then you say okay that percentage of our sample they get migraines that's a good estimate for the parameter of what percentage of my entire population actually gets migraines so this was clearly an experiment now the next question is well that was this experiment conducted well well even when I read it I was bothered by both groups were told which kind of feel they got that completely defeats the purpose of a placebo the placebo effect is hey I think I'm taking something good for me and it's been documented when you'd think you're taking a pill that helps you it oftentimes does help you and so if someone's coming up with a new medicine it better be better it better perform or we it better be more effective than just that placebo so I don't like the fact and this is this was like this is a very bad study to tell both groups what kind of pill they got you actually should tell neither group which type of pill they got