An article in Communications of the ACM (Vol. 30, No.

5, 1987) studied different algorithms for estimating software development costs. Six algorithms were applied to several different software development projects and the percent error in estimating the development cost was observed. Some of the data from this experiment is shown in the table below.

(a) Do the algorithms differ in their mean cost estimation accuracy?

(b) Analyze the residuals from this experiment.

(c) Which algorithm would you recommend for use in practice?

Project Algorithm 1 2 3 4 5 6 1(SLIM) 1244 21 82 2221 905 839 2(COCOMO-A) 281 129 396 1306 336 910 3(COCOMO-R) 220 84 458 543 300 794 4(COCONO-C) 225 83 425 552 291 826 5(FUNCTION POINTS) 19 11 −34 121 15 103 6(ESTIMALS) −20 35 −53 170 104 199