Hi All,

Regarding language use - please stop and consider what "rule of thumb" meant originally. In earlier American history, it was legal for a man to beat his wife with a stick providing the stick was no bigger in diameter than his thumb. I, for one, was horrified when I learned this and have vowed to never use the expression again.

Other phrases that could be used:
"general rule" 
"ballpark estimate" (OK if you don't mind sports analogies)
"general principle"
and so on.

Linda Smith, Pvt practice, Dayton OH