We would NOT pool the variances if
A) we had too few subjects.
B) we had too many subjects.
C) The means were clearly different.
D) we had very unequal sample variances.

Question

Quizplus · Accepted Answer

When the sample variances are very unequal, pooling them can lead to inaccurate results. In this case, we would use a Welch's t-test, which does not assume equal variances. Therefore, we would not pool the variances. The other options (A, B, and C) do not necessarily affect whether or not we pool the variances.

We Would NOT Pool the Variances If