Sample Size Tables for Correlation Analysis with Applications in Partial Correlation and Multiple Regression Analysis.

Tables for selecting sample size in correlation studies are presented. Some of the tables allow selection of sample size so that r (or r², depending on the statistic the researcher plans to interpret) will be within a target interval around the population parameter with probability .95. The intervals are ±.05, &plusmn.10, &plusmn.15, and &plusmn.20 around the population parameter. Other tables allow selection of sample size to meet a target for power when conducting a .05 test of the null hypothesis that a correlation coefficient is zero. Applications of the tables in partial correlation and multiple regression analyses are discussed. SAS and SPSS computer programs are made available to permit researchers to select sample size for levels of accuracy, probabilities, and parameter values and for Type I error rates other than those used in constructing the tables.