The method of Barker is a popular scheme for determination of activity coefficients from total pressure measurements. A comprehensive review of this method is presented in this study. While discussing this technique various aspects of (vapor + liquid) equilibrium (VLE) data reduction process including types of algorithms applied, roles of saturated vapor pressures and equilibrium vapor compositions data, and types of objective functions used are analyzed. Activity coefficient or liquid state models frequently used in VLE data reduction are shown and their comparisons are investigated. More so, advantages and limitations of Barker's method are demonstrated. (C) 2011 Elsevier Ltd. All rights reserved.