The representation of correlations between quantities by means of dimensionless products results in a reduction of the number of variables (according to a "rule of thumb," the number of independent dimensionless power products which can be formed from a given set of quantities is equal to the number of quantities involved, minus the number of basic measurable in terms of which these quantities are expressed) Taking this into consideration, what is the advantage of using dimensionless products for the experimental determination of correlations between quantities and for the graphical representation of functional dependences?