Qualitative : Factorial

Jill wants to test the efficacy of two treatments taken separately and also taken together. She will need to use a factorial design.

So far, we know that Jill is going to use a factorial design testing the effect of two treatments separately and when taken in conjunction on preventing the disease of interest. Another important factor for determining sample size is the number of times Jill plans on measuring the size of the tumor. For example, is she going to test whether the disease has occurred only at the end of the study or at several time points throughout the study. How many times will you be measuring the response variable? -- ErinEsp - 31 Jan 2010