# Can a confidence interval be greater than 1?

I am doing a classification task and obtain an accuracy of 97.5%. Now, I calculated the confidence interval, assuming a normal distribution, at the 95% confidence level with: Accuracy +/- 1.96*Standard Deviation (see Alex A Freitas, Data Mining and Knowledge Discovery with Evolutionary Algorithms (2002)). I am getting a value of 0.975 +/- 0.048. As this would be more than 1, can that be right?

• No, you're assuming normality, and that's wrong. Feb 5 '16 at 3:21
• Why would a variable that is bounded to be in $[0,1]$ be normally distributed? And how did you calculate that standard deviation? Feb 5 '16 at 6:26