14 pre-pubescent
children who are shorter than expected are recruited for a study of
synthetic growth hormones. The children are classified by gender and
by the degree to which their bone development is depressed
(i.e., slower than normal) and their current rate of bone
growth is recorded. Development depression is categorized as severe,
moderate, or mild. After treatment with a growth hormone, the new
rate of bone growth is recorded.  Our outcome is the difference in
rate of bone growth before and after treatment. 

These data come from:

Neter, Kutner, Nachtsheim, and Wasserman (1996). Applied Linear
 Statistical Models, 4th Edition, Irwin Press, ISBN 0-256-11736-5.