I'm stcuk, stuck stuck!!!

This is annoying me! I have to come up with original and hypothetical example of a Social Science study that has CAUSAL inference... and describe how to do an expt on it... and it is not just 1 example mind you.. it is 3!!! 3 examples! been racking my brains.. I think i killed loads of brain cells... and my page is still as blank as tabula rasa!

HELP!!!