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March 20[edit]

Confidence interval[edit]

What does it mean if something has a 95 percent confidence interval?

See confidence interval, and please feel free to come back if anything there is confusing or unclear. SemanticMantis (talk) 14:46, 20 March 2015 (UTC)[reply]

In frequentist statistics, it means that if we randomly sampled the parameter from the distribution a large number of times, and calculated a confidence interval around the parameter each time, then 95% of those intervals would contain the true value of the parameter. The best way I've heard this described is that we have confidence in the value of the parameter, not because we know it is contained in the interval 95% of the time (it isn't necessarily), but because we have confidence in the process used to construct the interval.OldTimeNESter (talk) 16:48, 20 March 2015 (UTC)[reply]