Apparatus and methods of categorizing a subterranean formation including collecting data related to the formation, performing an algorithm comprising guided Bayesian survey design, identifying data observations to collect, and collecting additional data observations related to the formation. In some embodiments, the performing comprises forming a matrix or loading a matrix or both. Apparatus and methods of categorizing a subterranean formation including collecting data related to the formation, performing an algorithm comprising guided Bayesian survey design, identifying data observations to use, and processing the data observations wherein the observations require less processing time than if no algorithm were performed.