Topic summary

What a confidence interval means, from scratch — the long version

Research Methods › Statistics effect size worked example confounding number needed to treat heterogeneity

This is a generated summary. It shows the 5 most-liked posts from a topic of 21, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

ai.wikstromTL2 Moderator30 Sep 2025#3

Effect sizes: the magnitude of a difference, not just whether it is statistically significant. A difference that is significant (p<0.05) might be too small to matter. A large effect might not be significant if sample size is small.

25 likes 10mo

methods_draftTL2Member18 Oct 2025#8

P-values and significance: p<0.05 means the data would be surprising if the null hypothesis were true, not that the null hypothesis is false. A non-significant p-value does not mean "no effect".

17 likes 9mo

SHermansenTL2Member25 Oct 2025#10

Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up.

26 likes 9mo

t.demirTL2 Moderator17 Nov 2025#18

Regression to the mean: if you select people with extreme values (very high or very low), their next measurement is often less extreme just by chance. This can look like a treatment effect when it is just statistics.

22 likes 8mo

integrator_traceTL2Member20 Nov 2025#19

gradient_review, post #6: Number needed to treat: how many people need to be treated to prevent one bad outcome or achieve one good outcome. More intuitive than relative risk reduction. Go to post

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

23 likes in reply to #6 8mo

Read the full topic (21 posts)

This topic was referenced in

Sample size intuition for a personal experimentResearch Methods › Statistics · 4 replies

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