I'm on the stage of experiment design of some biomedical time-course study. Let's say we will have 2 groups of subjects - case and control. The total number of subjects is limited (for example, 30), and we need to decide how it's better to split subjects between case and control. One way is to have balanced dataset 50% of case vs. 50% of control. Another way is to assign 2/3 of subjects to case and 1/3 to control, since the case subjects would be more interesting.
What experiemnt design would you suggest? Which issues/pitfalls should be considered in both case? Should the experiment design depend on questions asked?