The traditional approach of analyzing field emission (FE) data using the "emission area" and "field enhancement" factors is faulty. Instead, the emission current I should be computed through integration of the tunneling current density over the emitter surface, taking into account the local variation of the electric field. As a consequence, FE data represented as Fowler-Nordheim (FN) plots ln(I/V-2) versus 1/V are nonlinear regardless of the model used to derive the electric field and the modified FN plot ln(I/V-3) versus 1/V is more suitable for representing the FE data in a linear way. In this article, a general approach for extraction of model parameters using wide-range FE data is proposed. A nonlinear least-square fitting procedure is applied to emission data based on the statistical gated emitter/triode model tailored for the particular emitter configuration. Uniform distributions for the emitter radius R and work function phi in the array are considered, although other distributions may be included in the model. Deriving an accurate analytical formula for computing the electric field on the emitter tip is a crucial step for obtaining good modeling results. At least two model parameters from the set comprising R, phi and their dispersion range DeltaR, Deltaphi can thus be derived. Comparison with experimental results is provided. (C) 2003 American Vacuum Society.