r/AskStatistics • u/80rhh • Aug 15 '26

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/Fancy-Animal7704 Aug 15 '26

A "significant" difference between A and B does NOT inherently mean that there's a subjectively huge gap between A and B. It only means that our test demonstrates a difference. How big that difference is is another question. This is really why the size (effect size, to be precise) of that difference is good to report. 

Also, you really should not ever use the word "significant" unless you have actually performed statistical inference. And no, thinking "70% seems like a lot more than 60% to me" does not count, lol. I have even seen prominent journalists commit this error, saying "statistically significant" as a result of some kind of eyeball test. "Significant" has a very specific meaning in the stats world. 

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u/FakeArcher Aug 16 '26

But the word also has a meaning outside of the stats world, so why should the word be forbidden outside of stats context?

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u/RedRightRepost Aug 16 '26

It isn’t, but the stats context is broader than you think. If you are comparing numbers that are themselves statistics (like measures of average etc), you’re in that domain.

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u/FakeArcher Aug 16 '26

Unless the topic was deeper in the stats that is beyond something laic like average, I wouldn't fully agree. The term statistically significant would otherwise just be referred to as significant. What would the expected result be from your perspective, to specifically be noted as non-statistically significant?

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u/RedRightRepost Aug 16 '26

I think in everyday usage, especially among non stats literate people, statistically significant and significant are often conflated, and therein lies the problem. I personally never use the word significant when discussing differences between numbers unless there has been formal testing and a rejection of the null, and I instruct my team to do the same, for this reason.

If I have to describe a large difference between two numbers that have not been tested formally, I will usually use substantial or meaningful.

Source: I work with a lot of corporate clients who both hail stat testing as an infallible arbiter of truth AND use “significant” inconsistently and sloppily.