The basic philosophy of the Farrell technique is used in the model to be presented here, but the details show a number of important differences. The assumption of linear homogeneity is relaxed, but at the cost of specifying a functional form, in this case Cobb-Douglas. The frontier is thus estimated in input-output space rather than input-input space. The frontier is estimated in probabilistic fashion by constraining X percent of the observations to fall outside the frontier surface. Alternative nondeterministic specifications are also investigated. The resulting model and the estimation techniques resemble those recently presented by Aigner and Chu (1908) for a somewhat different purpose.