milosevic - 9:57 am on Nov 18, 2010 (gmt 0)

One is visual the other semantic

Based on what? I have seen no evidence that this is true and it makes no sense. Even if the spec suggests this is the case, what difference is there in the real world?

There's no evidence that browsers, screen readers or search engines treat these elements differently, so for developers to treat them differently is a fallacy.

See this article: [paciellogroup.com...]

"Using the semantic elements strong and em does not convey any useful information to users of JAWS or Window Eyes under typical browsing conditions."