1. A process for recoverying oil from a subterranean oil-bearing formation having performance demands comprising the steps of: determining said performance demands of said formation; determining correlations between an initial polymerization reaction parameter of initiator level and partially hydrolyzed polyacrylamide solution properties of screen factor and viscosity, each said correlation having a discontinuity; selecting a value of said initiator level below each said discontinuity such that said selected value of said initiator level is capable of producing a partially hydrolyzed polyacrylamide solution having values of said properties of viscosity and screen factor relatively sensitive to varying said initiator level and capable of meeting said performance demands of said formation; producing said partially hydrolyzed polyacrylamide solution having said values of said properties relatively sensitive to varying said initiator level and capable of meeting said performance demands by polymerizing an acrylamide monomer using a polymerization initiator at said selected value; and injecting said partially hydrolyzed polyacrylamide solution into said formation to improve oil recovery therefrom.