Everyone,
There has not been much activity in this discussion group. Meanwhile, I know of (and participate in) a very active discussion group more broadly focused on statistical methods, but with plenty of postings on sample-size-related issues. So I suggest that people go to that website instead of this one with questions on sample size. They are likely to get more responses, often from more experienced people. The forum I am suggesting is called Cross Validated, and its URL is http://stats.stackexchange.com.
Russell V. Lenth - Professor Emeritus
Department of Statistics and Actuarial Science
The University of Iowa - Iowa City, IA 52242 USA
Voice (319)335-0712 (Dept. office) - FAX (319)335-3017