Aggression rating

[cold_cash]

Okay, so I suck with numbers. This isn't exactly front page news around here, but I figured it was worth repeating.

Anyway, here's my question.

In PokerTracker and PokerAce, each player has an aggression rating. All of them are different. Of course there is an 'ideal' or 'preferred' range for those of us checking our own stats.

My question is how does a players looseness or tightness effect that number, and what does it mean to me?

For example, let's say Player A has a VPIP of 25% and a total aggression rating of 1.5, and Player B has a VPIP of 65% and a total aggression rating of 1.5.

Now obviously we see the same number (1.5) and think these players may be similarly aggressive, but that's not the case.

Your job is to tell me why.