Interpreting software output, continued. The SPSS output for the Bonferroni multiple-comparisons procedure given in Figure 12.15 includes the simultaneous 95% confidence intervals. We can see, for example, that the interval for μ1 − μ3 is −1.63 to 0.14. The fact that the interval includes 0 is consistent with the fact that we failed to detect a difference between these two means using this procedure. Note that the interval for μ3 − μ1 is also provided. This is not really a new piece of information because it can be obtained from the other interval by reversing the signs and reversing the order, that is, –0.14 to 1.63. So, in fact, we really have only 10 intervals. Use of the Bonferroni procedure provides us with 95% confidence that all 10 intervals simultaneously contain the true values of the population mean differences.