Offsets in abundances determined by applying the estimated uncertainties (one at a time) for effective temperature (top row), surface gravity (middle row), and microturbulent velocity (bottom row) to the corresponding parameters determined by GALA and then rerunning GALA with fixed parameters. The left column shows the effect of subtracting the uncertainties, the right one the effect of adding the uncertainties. Red open symbols (circle, square, triangle) mark the stars in NGC 6388, blue lozenges the ones in NGC 6397, and green crosses the ones in NGC 6752.