Dependence of ∆_s on the number of bins, and the NIV_∞. Each data point represents the intrinsic scatter in the NIV, determined from 2000 light curves, randomly selected from a 10⁵ bin simulated pink-noise light curve produced from a constant input PSD. The curves show the best fit relation of ∆_s(N_b), at fixed levels of NIV_∞, using Eq. (10) with parameter values as contained in Table 2. There is a significant scatter among the data points due to the probabilistic nature of this estimate.