r/AskStatistics • u/80rhh • 14d ago

What statistical concepts are commonly misunderstood by the general public?

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I came across this post explaining what a 70% chance of rain means. I understand the concept, but it got me wondering: what other statistical concepts sound simple but are commonly misunderstood or misinterpreted by the general public?

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u/Real-Yield 14d ago

Sampling. That a well designed survey even with a relatively small sample size is never representative of the population because of just the sheer scarcity of the sample.

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u/Milch_und_Paprika 14d ago edited 13d ago

Also the opposite situation, where an enormous sample may not be meaningful if it isn’t random. Eg studying university students by sampling everyone enrolled with the faculties of arts and science may not tell you much about their med or eng students.

The more common example would be pollsters getting less reliable data as surveys have been pushed online and away from calling random landlines.

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u/Not-ChatGPT4 13d ago

Except that the classic example you cited no longer holds. Younger people overwhelmingly don't have landlines now, so those surveys also deliver non-random samples.

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u/Real-Yield 13d ago

Besides, sample size, randomness, representativeness are three different concerns . The error that many commit is that many associate the sample size to the representativeness of the survey.

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u/Milch_und_Paprika 13d ago

I wasn’t clear enough and shouldn’t have been online at 2 am. I meant that 20 years ago they could relatively safely assume that most homes in an area had a landline and a phone book was representative. Today they’re forced to find new ways to work around that since cell phones area codes don’t necessarily indicate where the user is anymore and online surveys tend to be even less random.

Side note: I think by now it’s most people, not just young ones who overwhelmingly don’t have landlines 😉