Definitely define it both ways. Unfinished and finished. I have been in groups where both measurements were given and explained and still some don't 'get it' and submit blocks the wrong size.
Unfinished = the actual individual block size before it is put int the quilt and includes the 1/4" seam allowances all around it.
Finished = the size of the block once it is sewn into the quilt - where the seam allowances don't show - and where you want any points to end so as not to be in the seam allowances.
ali