Analytic rheology is the subject of determining the microstructure of a material from measurements of its viscoelastic response. Analytic rheology is an extension of analytic chemistry in much the same sense as other analytic methods predicated on flow properties. Intrinsic viscosity is an example of an analytical technique that falls into this category. Analytic rheology can be applied to any material system where the rheological response depends strongly on the microstructure. There are many examples of such systems in rheology. For example, the droplet size distribution of a multiphase suspension can be determined from the measured linear viscoelastic response. Experimental methods of determining the linear viscoelastic material functions are highly evolved such that accurate and reliable measurements can be made in a routine highly automated manner. Analytic rheology exploits this experimental capability and develops advanced methods of interpreting and utilizing standard rheological measurements. With advanced data interpretation methods such as MWD determinations, the TAOrchestrator software allows the full power of rheological characterization methods to be realized. The specific application of analytic rheology that we are concerned with in this document is the calculation of the molecular weight distribution for linear flexible polymers from measured linear viscoelastic material functions.