Two major goals in the study of biological systems are inference andprediction. Inference creates a mathematical model of the datageneration process to formalize our understanding or test ahypothesis about how the system behaves. Prediction aims atforecasting unobserved outcomes or future behavior, such as whethera mouse with a given phenotype will have a disease. Prediction makesit possible to identify best courses of action (e.g. treatment choice)without requiring understanding of the underlying mechanisms. In atypical research project, both inference and prediction are of value—we want to know how biological processes work and what will happennext. For example, we might want to infer which biological processesare associated with the dysregulation of a gene in a disease as well asclassify whether a subject has the disease and predict the besttherapy, such as drug intervention or invasive surgery.