Outputs from different fitting methods performed on a simulated galaxies with average age = 3.4 Gyr ( = 9.53 dex) and [M/H] = 0.06 dex (black cross), not extinguished (a) and extinguished with a Calzetti reddening curve using E(B-V) = 0.1 (b). The error bars are the typical errors estimated for the age and metallicity in Appendix B, 0.07 and 0.06 dex, respectively. Fits are performed using multiplicative polynomials of degree 2, 6, 10, and 14, a Calzetti reddening curve, and a combination of a Calzetti reddening curve and multiplicative polynomials of degree = 4, as indicated in each panel. Markers represent the output values at different S/N, ranging from 5 to 100, with darker colors representing higher S/N values.