It increases the washout on the wing (not full span ailerons) This will help make the stall less sudden and decrease the chance for an uncoordinated stall, AKA "tip stall." It will not prevent a stall and is only helpful if you do not have built in washout. As long as the A/C is built properly, learning the envelope of your A/C, and staying within that envelope, is a much better idea. It will fix an improperly built/designed A/C.