Candidate regressions included in super learner analysis of the RTS,S/AS01 data for estimation of iterated means. GLM = logistic regression; GAM = generalized additive model; GBM = gradient boosted machine. A variable selection was included in some candidate regression algorithms (third column). In some cases, variables were selected a-priori; in others, variables were selected based on their correlation with the outcome. Gradient boosted machine tuning parameters selected based on out-of-bag (OOB) error rate.