Computing and comparing correlation and regression coefficients using a pocket calculator
Programs suitable for pocket calculators using reverse Polish notation are described. Pro- gram 1 computes regression coefficients, correlation coefficient, and standard error of esti- mate for paired data. Program 2 performs a t test to compare.the slopes of two regression lines. Program 3 computes F ratios to test the departure of a regression slope from zero and to test linearity of the regression. Programs 4 and 5 test the significance of differences between inde- pendent and correlated correlation coefficients, respectively. Although the development of inexpensive microcom- puters has brought considerable computing power within the reach of most scientists, the portability and ready availability of the pocket calculator remain a considerable advantage for those who work some distance from the nearest computer or those who have to queue to use it. Most manuals for pocket calculators provide several elementary statistical programs, usually including computation of correlation and/or regression coef- ficients, but, to my knowledge, none go beyond these simple statistics, and most are rather clumsy, requiring, for example, that separate programs be used for correla- tion and regression, so that the data have to be keyed in twice. The programs described here overcome some of these limitations. The programs were devised for a

Published in 1980.