After receiving a promotional email from Elsevier, DrugMonkey considers what constitutes a noteworthy change in a journal's impact factor at his blog this week. The email, he says, advertises that one of the publisher's many titles saw a 0.336 boost in its impact factor from 2010 to 2011.

"Is this a significant difference? Who gives a hoot if the IF [impact factor] goes up by 0.336?" DrugMonkey asks. "Is this in any way meaningful?"