This method is also known as Experts opinion methods of investigation. In this method instead of depending upon the opinion of buyers and salesmen firms can obtain views of the specialists or experts in their respective fields. Opinions of different experts are sought and their identity is kept secured. These opinions are then exchanged among the various experts and their reaction sae sought and analyzed. The process goes on until some sort of unanimity is arrived at among all the experts. This method is best suited in circumstances where intractable changes are occurring.