1. A method of assessing error rates and tuning parameters associated with policy based procedures for verification of a plurality of known speakers through the use of conversational biometrics, evolution of the policy based procedures being controlled by a state machine and each of the plurality of known speakers has an associated acoustic component and a knowledge profile, the method comprising the steps of: performing a policy based verification using a finite state machine defined by a set of states, each state having a specified set of questions and a plurality of possible state transitions, a state transition being performed if a condition of a state transition path associated with the state transition is satisfied; determining allowability of the condition; generating a state transition path through the state machine; identifying all allowable state transition paths; developing a probabilistic analysis of the behavior of the state machine, wherein each allowable state transition path is assigned a probability value; generating a Receiver Operating Map (ROM) by using said probability values; mapping a set of thresholds/parameters to a false accept rate and a false reject rate by using an acoustic Receiver Operating Curve and probabilities of knowledge error, wherein the ROM is a function of a plurality of the thresholds/parameters with an output selected from one of accept rate and reject rate; and tuning said thresholds/parameters by visually or analytically examining and optimizing over the ROM.