Warning Signs in Experimental Design and Interpretation (2007) • Hacker News Board

Re: Warning Signs in Experimental Design and Interpretation (2007)

#11

Post by jfoutz » Tue, Jan 08, 2019, 1:50 AM UTC

Larrikin wrote: post #8

throwaway6356 wrote: post #6

> Lack of Double-Blind Studies "We know there is a placebo effect wherein patients do better when they are told they are receiving a treatment: the patients' expectations play a role in their recovery. To make sure we are studying the effect of the treatment itself and not the patients' expectations, it is better to give all patients the same expectation. So we tell them, for example, "take this pill, it might be exp…

It seems that it would be unethical, for example, to make someone intentionally sick to mimic the side effects of the drug with none of the expected positive results.

Yes. Yes it would. But comparing against baby aspirin might be worthwhile. There is some (safe?) effect beyond sugar pills.

Remember, the patients don’t know each other, and don’t compare symptoms. Hopefully.

Re: Warning Signs in Experimental Design and Interpretation (2007)

#12

Post by the_af » Tue, Jan 08, 2019, 4:07 AM UTC

pierrebai wrote: post #4

I slightly dislike that his opening paragraphs are wrong. The statement "The group with treatment X had significantly less disease (p = 1%)" does not mean "treatment X it will prevent disease." It only means that there were less disease with a significant probability of being true. IOW, the study might be 99% sure it reduces the disease by 5%.

But Norvig is asserting that many people interpret the first statement as "it's almost sure treatment X will prevent disease in my case". It's an example of a case where common sense misleads us.

Re: Warning Signs in Experimental Design and Interpretation (2007)

#13

Post by ytpete » Tue, Jan 08, 2019, 5:13 AM UTC

throwaway6356 wrote: post #6

> Lack of Double-Blind Studies "We know there is a placebo effect wherein patients do better when they are told they are receiving a treatment: the patients' expectations play a role in their recovery. To make sure we are studying the effect of the treatment itself and not the patients' expectations, it is better to give all patients the same expectation. So we tell them, for example, "take this pill, it might be exp…

There are two known phenomena related to this:

* "Unblinding," where participants are able to figure out whether they're taking the placebo vs. the real medication by noticing whether they experience any side effects.

* The "nocebo" effect, kind of a reverse placebo effect where participants in the control group experience false side effects because they believe they might be in the experimental group taking the real medication.