Figure 1.

TDR to detect genotype effects under all approaches to handling covariates using Random Forests: For all models Z effect is fixed at 0.5 except for Model 3 where Z = 2. For Model 2, corr(X₁, Z) = 0.5. For Models 1–3 X₁ effect is varied over [0.1,0.9] while for Models 4–6 the effect sizes of main effects, if a model has main effects, are fixed at 0.5 and the effect size of the interaction term is varied over [0.1,0.9].