Fig. 5.

SPSS output for the comparison of the mean age between two groups. Framed in green, we see the Levene test for equality of variances, which SPSS automatically applies when we compare means with a t-test. A significant p Value for the Levene test means that homogeneity of variance cannot be assumed. Therefore, the second line from the SPSS output (framed in dark blue) “equal variances not assumed” contains the p value from the correct t-test (Welch’s t-test). In Fig. 5, the p value for the Levene Test is > 0.05, which means that homogeneity of the variance can be assumed: The upper line, framed in orange, contains the correct t-test (Student’s t-test); the p value we are looking for is p = 0.129