Pairwise comparison of the bias (top panels) and the dispersion (bottom panels) between three different methods as indicated in each panel. The results are plotted as a function of effective temperature (x-axis) and signal-to-noise ratio (y-axis). The colours are identified with the method names in each panel; each point is given the colour of the method with the smallest bias (top row) or the smallest dispersion (bottom row) respectively. Filled symbols indicate that the difference is statistically significant at the 0.2% level in a two-sided test.