Relation between the model-derived SFR (averaged over the past 100 Myr) and various measures of the FUV luminosity. The observed values are indicated by red circles and are offset from their intrinsic value because of extinction. The intrinsic FUV luminosities, derived from the model, are shown as blue diamonds and fall on the solid blue line given by Equation (10). Region numbers are listed in the figure. A detailed discussion is in the text (Section 5.1).