Below each graph is a summary of the results of statistical
tests examining differences in group means. We utilized
analysis of variance (ANOVA), which tests for signifcant
differences between group means (in conjunction with
partitioning the observed variance). In contrast to the more
familiar t-test, which only allows for the comparison of two
groups, ANOVA allows for the comparison of more than
two groups (in this case four groups). Note that we also
conducted analyses of covariance (ANCOVAs) controlling
for student Socioeconomic Status (SES) and the results were
essentially the sam