Equivalence of the Pearson and Ayes Formulas of Correlation
George C. Kyte · The Journal of Educational Research · 1953
IN THE FIRST volume of the Journal of Educational Research, Leonard P. Ayr es published his shorter method for computing the co efficient of correlation. * It is the method which gives the sums of the products and the sums of the squares of the deviations directly from the squares of the original numbers. method avoids the necessity for taking into account the plus and minus signs of devia tions. Ayres' formula was based upon his stated principle: This method is based upon considering every number in a series as being equal to the average of the series plus a plus or minus deviation from the aver age. Letting Sub. = the first, or subject series Rel. = the second, or relative series Tot. = the total of the series, the sums of the items Av. = the average of the series, he formulated the statement of his method correlation as follows: