For those who want to see an example of this, see the first shot in:That's exactly how the scoop shot works as explained by Dr. Dave. You slide your stick along the cloth to hit the bottom of the ball and the cue ball jumps not because of a miscue but because the table is the mass on the other side. It's a totally unnatural shot, but try it to see if you can jump without a miscue. Make sure the edge of your tip is chalked well.
HSV B.2 - Illegal "scoop" jump shots
And for more info, see the illegal "scoop" jump shot resource page.