Bubble Aggressiveness: When is it appropriate?

[erocplayer]

I know becoming aggressive on the bubble is a common strategy, and I like to do it as well when I feel comfortable enough in my tournament position; however, I am not the strongest player around and usually approach the money on a relatively shortstack.

Assuming the hero is playing a 7-9 handed table, how many BBs, or what level M, would be appropriate for employing the aggressive bubble strategy? Is their an ideal number, or like seemingly everything in poker, is it just completely situational?

-eroc