Howtosignalprocessing
What does a negative confidence interval mean?
In simple terms, a negative confidence interval in this setting means that although observation is that mean of group 2 is 0.028 higher than group 1, the 95% confidence interval suggest that actually group 1 may be higher than group 2.
Should confidence interval be negative?
Only in the sense that one or more of the bounds (upper or lower) of the confidence interval can be negative, depending on the range of the data. The interval itself (upper-lower) will necessarily always be positive.
