I want to do a t-test for two independent samples with unequal variances. How do I perform Welch test in Statistica?

How to do Welch test in Statistica?

Windows

To do a t-test for two independent samples with unequal variances, you can tick the option "t-test with separate variance estimates" in Statistica t-test (by variables or by groups depending on your data structure), which is also called the Welch t test. 

Below  is a screenshot from Statistica e-manual. 



1. If your data have two variable columns storing the measurements for the two independent samples, go to Statistica menu "Statistica > Basic Statistics > t-test, independent, by variables", select the two Dependent variables, under t-test dialog "Options" tab, there is the option "t-test with separate variance estimates":



Tick that option and the result dialog will include statistics from t-test with separate variances calculated for the two samples.



2. If your data stores the measurements in one column and has another grouping column representing the two independent samples, go to Statistica menu "Statistics > Basic Statistics > t-test, independent, by groups", select Dependent and Grouping variables, under t-test dialog "Options" tab, there is the option "Test w separate variance estimates":



Tick that option and the result dialog will have statistics from t-test with separate variances calculated for the two groups.