Exercise: breast pump trial, 2
What effect might each of these problems have on the t test?
Treating repeated observations by the same method as independent gives us a false idea
of the amount of information.
This makes P values smaller than they should be.
Carrying out a two sample t test on paired data means that all the variation between women
goes into the random variation.
This tends to make the P value too large.
Carrying out a test when variances are unequal and distributions skew may make the P value too large.
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