TY - GEN AB - This dissertation develops a novel stochastic tree ensemble method for nonlinear regression, which I refer to as XBART, short for Accelerated Bayesian Additive Regression Trees. By combining regularization and stochastic search strategies from Bayesian modeling with computationally efficient techniques from recursive partitioning approaches, the new method attains state-of-the-art performance: in many settings it is both faster and more accurate than the widely-used XGBoost algorithm. Via careful simulation studies, I demonstrate that our new approach provides accurate point-wise estimates of the mean function and does so faster than popular alternatives, such as BART, XGBoost and neural networks (using Keras). This dissertation also prove a number of basic theoretical results about the new algorithm, including consistency of the single tree version of the model and stationarity of the Markov chain produced by the ensemble version. Furthermore, I demonstrate that initializing standard Bayesian additive regression trees Markov chain Monte Carlo (MCMC) at XBART-fitted trees considerably improves credible interval coverage and reduces total run-time. AD - University of Chicago AU - He, Jingyu DA - 2020-06 DO - 10.6082/uchicago.2324 DO - doi ED - P. Richard Hahn ED - Nicholas G. Polson ED - Tengyuan Liang ED - Ruey S. Tsay ID - 2324 KW - Statistics KW - Computer science KW - Bayesian KW - Machine Learning KW - Markov chain Monte Carlo KW - Regression Trees KW - Supervised Learning KW - Tree ensembles L1 - https://knowledge.uchicago.edu/record/2324/files/He_uchicago_0330D_15292.pdf L2 - https://knowledge.uchicago.edu/record/2324/files/He_uchicago_0330D_15292.pdf L4 - https://knowledge.uchicago.edu/record/2324/files/He_uchicago_0330D_15292.pdf LA - eng LK - https://knowledge.uchicago.edu/record/2324/files/He_uchicago_0330D_15292.pdf N2 - This dissertation develops a novel stochastic tree ensemble method for nonlinear regression, which I refer to as XBART, short for Accelerated Bayesian Additive Regression Trees. By combining regularization and stochastic search strategies from Bayesian modeling with computationally efficient techniques from recursive partitioning approaches, the new method attains state-of-the-art performance: in many settings it is both faster and more accurate than the widely-used XGBoost algorithm. Via careful simulation studies, I demonstrate that our new approach provides accurate point-wise estimates of the mean function and does so faster than popular alternatives, such as BART, XGBoost and neural networks (using Keras). This dissertation also prove a number of basic theoretical results about the new algorithm, including consistency of the single tree version of the model and stationarity of the Markov chain produced by the ensemble version. Furthermore, I demonstrate that initializing standard Bayesian additive regression trees Markov chain Monte Carlo (MCMC) at XBART-fitted trees considerably improves credible interval coverage and reduces total run-time. PB - University of Chicago PY - 2020-06 T1 - XBART: A Scalable Stochastic Algorithm for Supervised Machine Learning with Additive Tree Ensembles TI - XBART: A Scalable Stochastic Algorithm for Supervised Machine Learning with Additive Tree Ensembles UR - https://knowledge.uchicago.edu/record/2324/files/He_uchicago_0330D_15292.pdf Y1 - 2020-06 ER -