OK, so I was trying get a formula in calculated column to recognize the Yes/No field (check box), this is not the choice field. You would think that you could check to see if the filed is yes or no, but that turns out not to be the case.
I read a few posts and the data is stored in Boolean, so I tried 1 or 0 as some post said, but that did not work. I then stumbled upon a post that said to use True or False, that worked.
Here is an example:
WORKED:
=IF(Attending=TRUE,"Attending","Not Attending")
Did NOT work:
=IF(Attending="Yes","Attending","Not Attending")
=IF(Attending=1,"Attending","Not Attending")