Evolution of volunteer skill parameter statistics versus number of subjects inspected. The top panel show the distribution of the number of volunteers who have inspected at least as many subjects as indicated by the upper boundary of each bin. This means volunteers who annotate many subjects will contribute to several bins. However, their skill parameters are sampled at the point that they had inspected the maximum number of subjects represented by a particular bin. Statistics for the different volunteer skill parameters |$p_{j}^{\mathrm{fp}}$|⁠, |$p_{j}^{\mathrm{fn}}$| and σ_j are shown in the upper-middle, lower-middle, and bottom panels, respectively. Red and blue markers plot the median and mean skill parameter of all volunteers contributing to a particular bin, respectively. The orange band illustrates the inter-quartile ranges of the bin-wise distributions. Dotted and dashed lines indicate the 5th and 95th percentiles, respectively.