Top: time evolution of the ratio of the SFR measured using the populations of YSOs found in different classes (full lines) and the total population (dashed line) and the real SFR that is generated in the models. Each line is an average over 250 clusters. Each cluster has N_* = 500, a Milky Way-like IMF, and a Gaussian-like SFH with the peak of the Gaussian located at t_b,p = 2 Myr and a standard deviation of σ_t = 0.5 Myr. Bottom: similar to the top panel, but with t_b,p = 2 Myr and σ_t = 2 Myr. For improved clarity, the 1σ uncertainties are not shown.