Author: Jonathan Osters

This lesson will explain placebos in experiments

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This tutorial is going to talk to you about placebos and the Placebo Effect.

Now placebo is a sham treatment. People can respond to thinking their receiving a treatment. So it's inert. It doesn't do anything. It has no active treatment. But people feel better anyway. They've sort of willed themselves well. This is called the Placebo Effect.

And a placebo itself is a treatment received by the control group, always by the control group. The treatment group gets the actual drug. And the control group gets the sham drug. It has no active ingredient in it. This is usually some kind of a sugar or something. It doesn't do anything. It has no active ingredient. But the subject may feel better anyway.

Now it's possible that the treatment that has the actual drug in it doesn't work any better than the placebo, which does nothing. That's actually evidence against the treatment working. Suppose that you had the treatment that relieved pain. Suppose we were doing some kind of a pain study. And it relieved pain in 42% of the patients. Whereas the placebo, which doesn't do anything, relieved pain in 36% of patients.

Well 42 and 36 are not that far apart. These results would be weak evidence for the effectiveness of the drug. Whereas something like this. If the treatment is effective it will have a substantially higher relief rate than the placebo. We might still have 36% of patients in the placebo group reporting a relief of pain. But if that number is up to somewhere around 80% for the treatment group that is evidence for the effectiveness of the drug.

And so to recap placebos are a form of control. They're a fake drug. People can respond to thinking their receiving a treatment. And so that's why we use a placebo rather than just saying OK well you're not going to receive any treatment. Because we want people to possibly will themselves well. And that could happen if they're taking the treatment as well. They're just willing themselves well. So we want to know what percent of people are actually responding to the active ingredients in the treatment.

So experimenters will assess the effectiveness of the treatment against the effectiveness of the placebo. And again we talked about the placebo, which is the sham drug and the Placebo Effect, which is people feeling better after having not done anything within any active ingredient. Good luck. And we'll see you next time.

Terms to Know

An inert drug or treatment given to the control group. It has no active ingredient in it.

Placebo Effect

The observed phenomenon whereby certain individuals will exhibit a desired response even when taking a placebo, which contains no active ingredient.