The properties of soil and rock are the results of the natural processes that have formed them, and natural or man-made events following their formation.  Having obtained the data from the field investigation and laboratory testing program, the focus of the engineer’s efforts turn to the reduction and evaluation of these data, the definition of subsurface stratification and groundwater conditions, the development of appropriate soil and rock design parameters, and the presentation of the investigation findings in a geotechnical report. The engineer uses this acquired subsurface information in the analysis and providing design criteria for foundations and other geotechnical elements.