Confidence Interval
Etymology
Coined by Jerzy Neyman in 1937. “Confidence” is from Latin “confidere” (to trust fully), from com- (intensive) plus fidere (to trust); the “confidence” refers to the long-run reliability of the method, not to any single interval.
noun phrase · /KON-fih-duhns IN-ter-vuhl/
A range of plausible values for an estimate, together with how often such ranges would capture the truth.
What it names
It replaces false precision with an honest band, reminding you that an estimate is a guess with a width.
Example
An estimate of “12 percent, 95 percent confidence interval 8 to 16 percent” is far more honest than the bare figure of 12 percent.
Related idea
A confidence interval expresses the same uncertainty as a margin of error but names the range directly; strictly, the “95 percent” describes the procedure over many samples, not the odds that this one interval contains the truth.