Principles of Web Development
The strong tag in HTML 4.01 emphasizes text and in HTML5 it defines important test. It also supports global and event attributes in HTML. I would say you would use it when you want to put a word in bold so the user will see it immediately. I wouldn't use it a whole lot then your page would get really messy and if there is to much then the strong tag would loss it's importance.
Do you agree or disagree with the above statement and why?