Fig. 7.

Mean of the (a, c) logarithmic loss function (MLLF) and (b, d) quadratic loss function (MQLF) from cross-validation, plotted against the concentration threshold, *z*_{T} (μg kg^{−1}). All plots show results from S: simple nongeostatistical method. (a) and (b) compare methods built on imputed (IM) and censored (CM) data with fixed effects selected for mapping (population density). (c) and (d) use the censored data approach to compare the fixed effects functions: no fixed effects (CO), fixed effects selected for mapping (population density, CM) and fixed effects selected for explaining PCB data (population density and soil organic carbon, CE).