Final answer:
In an ANOVA, Welch's correction is used to correct for unequal group sizes.
Step-by-step explanation:
In an ANOVA, if the group sizes are unequal, one way to correct for this is to use Welch's correction. Welch's correction adjusts the degrees of freedom in the calculation of the test statistic to account for unequal group sizes.
It is particularly useful when the assumption of equal variances is violated.
Trimmed means and Bonferroni correction are not specifically used to correct for unequal group sizes in ANOVA.
The Mann-Whitney U test is a non-parametric test used to compare two independent groups, but it is not used directly to correct for group size imbalances in ANOVA.