shaco q + infinity edge damage? (rioters greatly appreciated)

http://leagueoflegends.wikia.com/wiki/Shaco

Deceive's damage bonus replaces the normal critical strike modifier, causing it to actually do less than a normal critical until the skill is at least at rank 4. It is affected by critical damage bonuses like Infinity Edge item.png Infinity Edge.

The wiki is your friend.

To make it clearer, IE should read "Critical Strikes now add another 50% of your Attack Damage". So, if I'm not mistaken, Shaco's Q + IE adds 50% more of your AD to his Q without IE.

IE adds 50% AD onto your crit, so it Does help your damage (easily testable in game). that being said, it is not that good of an item for shaco when you run the numbers, unless you're super fed 1 shot-o.