FIGURE 4.

Cumulative probability models generate accurate predictions for total microbial load and taxon-specific absolute abundances. Performance measures from 10-fold cross-validation of total microbial load model indicate predictive errors are constrained far below one order of magnitude (A). For visualization, bounded metrics vary between 0 and 1, while unbounded metrics vary in the positive real line. Similar results were observed in the held-out test set (B). 10-fold cross validation for taxon-specific predictions using hierarchical CPM indicates predictive performance varies across bacteria, although still far below one order of magnitude (C). Similar results were observed in the held-out test set (D). Predictions based on class of highest probability are indicated with (CHP) in the x-axis, and expectation-based counterparts are indicated likewise. MALR: mean absolute log-ratio; MAEr: mean absolute error relative to true values; D_xy: Somers’ Delta measure of ordinal association; Coverage: observed coverage of 95% predictive interval.