Prereq: None. Coreq: 15.060; or permission of instructor. Introduces core concepts and methods in data-driven modeling that inform and optimize decisions under uncertainty. Teaches modeling and computational skills (R and Julia). Covers topics such as time series forecasting, choice modeling, queuing theory, network models, dynamic programming, mixed-integer programming, stochastic optimization, matching algorithms, multi-armed bandits. Draws on real-world applications from retail, healthcare, logistics, supply chain, social and online networks, sports analytics, social applications, and online learning.