Rich Ulrich wrote:
>You can use t-tests
>effectively on outcomes that are dichotomous variables, and you use
>the pooled version (Student's t) despite any difference in variances.
>That is the test that gives you the proper p-levels.
Rich, if the sample sizes in the two groups are different, you have to use
the t test jigged for unequal variances. That's what my simulations showed.
Your other commments about the robustness of t tests for Likert scales are
reassuring, and thanks for responding. I did find that the confidence
interval went awry when responses got too stacked up on the first or last
level.
Will
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