This paper takes an evaluative look into OO methods and especially the evolution of the new Unified method from its ancestors, OMT and OODA. The paper tries to classify the components of the earlier methods and identify the parts that have been taken into the Unified method. The research applies the method metrics approach. For the sake of compactness we limit ourselves to the class diagram technique of all methods. We make observations about the number of concepts in each variation and show how the metrics can be used to analyse the changes in the techniques.