Comparison of Several Algorithms for Computation of Means, Standard Deviations and Correlation Coefficients Several algorithms for computation of basic statistics are compared by their performance on systematically generated test data. The statistics calculated were the mean, standard deviation and correlation coefficient. For each statistic, the algorithm included the usual computing formulas, correction due to an accumulated error term, and a recursive computation of the current value of the statistic. The usual computing formulas were also evaluated in double precision. Large errors were noted for some calculation using the usual computing formulas. The most reliable technique was correction of the initial estimate by use of an accumulated error term. To eliminate the need for making two passes on the data, it was suggested that the initial estimate of the mean be obtained from a subset of the data. CACM July, 1966 Neely, P. M. CA660703 JB March 6, 1978 2:54 PM 1411 5 1411 1411 5 1411 1411 5 1411 1619 5 1411 3166 5 1411 1411 6 1411 1411 6 1411 2731 6 1411 2799 6 1411 3159 6 1411 3167 6 1411