Double-click an interval and click the Options tab.
Choose a Type of Interval:
Confidence interval (default): a vertical line with horizontal lines at the end points of the 95% confidence interval for the mean. Confidence levels can apply to the individual intervals or the family of intervals (Bonferroni).
Standard error: a vertical line with horizontal lines at one standard error (or a multiple of the standard error) from the mean. The standard error of the mean is calculated by dividing the standard deviation by the square root of n (sample size).
To change the interval type for all subsequent interval plots, choose Tools > Options > Individual graph > Interval Plots and choose a different interval type.