data validation & formulas

Hello great folks who have saved me more than once:

I have a data validation list (drop down list) in one
cell, which offers a choice of 3 different selections; in
the next cell I have a formula (would like to have a
formula for each validation). Is it possible to create a
formula that says if this is chosen in the data validation
box, use this formula, if something else is chosen from
the drop down box use another formula, etc? Thus, a
different formula for each choice in the validation list.
Thank you in advance