The method of intermingling of solid particles in a mixing operation has great significance in finding suitable equipment and conditions to render the process more effective. After a survey of various mixing mechanisms, this paper deals with the principal possibilities for their identification, and gives several methods to evaluate artificial concentration patterns resulting from simulating diffusive-type and convection-shear mixing. In addition to the frequency distribution of the sample concentrations, the correlation technique, fractal analysis, phase-space technique, etc., are discussed.