Specific mathematical fields include geometry and analytical mechanics. These models provide either analytical or numerical solutions. The GPS equations can be solved by numerical and analytical methods. Most analytical techniques use a calibration curve. Water samples may be examined using the principles of analytical chemistry. Success is achieved by using combinations of analytical, creative, and practical intelligence. Hart sought to provide a theory of descriptive sociology and analytical jurisprudence. Such data problems can also be identified through a variety of analytical techniques. Symmetries in mathematics greatly simplify the study of geometrical or analytical objects. This is the basis of a powerful technique in analytical chemistry. The method is also used for the quantification of sedimentation velocity data from analytical ultracentrifugation. Buffer solutions also play a key role in analytical chemistry. This section was replaced by the Analytical Writing Assessment. Supplementary modules assist in the analytical process. Most involve collection of samples, followed by specialized analytical tests.