Equations are derived to enable the graphic approximation of the item parameters of the stochastic mental test models, i.e., the generalized normal ogive and logistic models. The item parameters for the models are discriminatory power, difficulty, and probability of chance success. Suggested uses for the approximations were to provide a basis for screening items for tailored testing, to enable a determination as to the appropriateness of a set of items for tailored testing, and to provide starting values for parameter estimation in maximum likelihood procedures. The conditions and assumptions necessary for an effective application of the method were delineated. Recent empirical results which bear on the properties of the approximations were examined. An investigation was suggested to evaluate a further possible use of the approximations--that of their direct applicability in tailored testing procedures. (Author/DLG)