From Figure 1 and 2 we can see that the 95%CIs for an one-samnple case far from the skewness value of zero is deemed that a statistically significant difference in an attitude
toward positive (with a negatively skewed distribution if higher scores represent positive) or toward negative (with a positively skewed distribution if lower scores represent negative) is found (p < .05). However, for the two-sample case it should be cautious about interpreting the graphical reports when examining the attitude difference between groups by non-overlapping 95%
confidence intervals (CIs). According to the criterion of 95% CIs derived from two independent samples(e.g., A and B), there is a distance beyond 2*SE_A + 2*SE_B between those two means with more than 95% confidence to regard as a significant difference emerged between two groups. That is said that (1) bootstrapping approach is especially suited to data following a non-normal
distribution; (2) the strict criterion of 95% CIs derived from two independent samples shows that MB - MA > 2 × SE_A + 2 × SE_B > 2 × sqrt(SE_A^2 + SE_B^2) which holds a high confidence to regard as a significant difference emerged in two groups by checking non-overlapping
95% confidence intervals (CIs).