has part has specified value confidence interval 95% confidence interval 95 Alejandra Gonzalez-Beltran Orlaith Burke Philippe Rocca-Serra STATO a confidence interval which covers 95% of the sampling distribution, meaning that there is a 5% risk of false positive (type I error). If the number of observations made is large enough, the sampling distribution can be assumed to be normal, which entails that 95% of the sampling distributions falls within roughly2 (1.96) standard deviations from the mean. confidence interval at 5% of type I error rate http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2689604/ confidence level ready for release