Question

Discuss the possible problems, if any, when utilizing an independent t-test with unequal groups.

Answer 1

When utilizing an independent t-test with unequal groups ( n1 is very much different from n2) and in addition when the total sample size is small (n = n1 + n2 < 30);

Possible problems:
The condition of applying t - test is that the two populations have equal variances. But, when the sample sizes are small and further one sample size is very much different from the other, the condition of equal variances may not be satisfied and hence t - test becomes inappropriate.

A non-parametric test such as Wilcoxon - Rank - Sum test is to be applied instead of independent t - test for unequal groups of small samples.