Mmmmm!
Barto is correct, positive incidence on the stab's leading edge is above the level line, which will cause the airplane's nose to go down. The degrees of incidence either on the wing or on the stab are measured from a center line, which runs horizontally along the length of the fuselage, this line is used as to have a reference point to set wing and stab incidence and also to set down or up thrust on the engine, remember that up (positive) incidence on the stab causes the airplane's nose to go down, but positive or up incidence on the leading edge of the wing causes the nose to go up.