When running an A/B test in python with scipy stats, we haven argument call: equal_var.
But basically it means: If True (default), perform a standard independent 2 sample test that assumes equal population variances . If False, perform Welch’s t-test, which does not assume equal population variance .
I wonder, if A & B are from the same population before the start of the experiment, we should set this parameter as True, right?
I have seen that a lot of examples set them as False, but it seems that is more when comparing means of two distribution, not necessary from the same population, in which case, makes sense.
Is this correcto?