Assessment of estimator performance by posterior predictive expected squared error for the paired tomato data sets. Total posterior predictive squared error (defined by equation (34)) relative to that of the gold standard model (the local-FDR mean expression estimator calculated using t-statistics and the theoretical null, labeled "t stat. with locfdr" in the figure) for 0, 3, and 10 day tomato data sets. Algorithm definitions are the same as those of Figure 1. Results for the 3 day and 10 day tomato data sets with the "all nulls true" estimator are greater than 1.1 and are not plotted.