title: Logarithmic transformations in ANOVA.
abstract: A method is presented for choosing an additive constant c when transforming data x to y = log(x + c). The method preserves Type I error probability and power in ANOVA under the assumption that the x + c for some c are log-normally distributed. The method has advantages similar to those of rank transformations--namely, it is easy to use and is resistant to extreme observations. Since the special case c----infinity corresponds in ANOVA to y = x, the method is a useful generalization of least squares.
authors.forename: D A
authors.initials: DA
authors.lastname: Berry
mesh_terms: D000704:Analysis of Variance; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000188:drug therapy*; D002986:Clinical Trials as Topic; D004077:Digoxin / Q000097:blood; D004311:Double-Blind Method; D004358:Drug Therapy / Q000379:methods*; D006197:Hair; D006352:Heart Ventricles; D006801:Humans; D012107:Research Design; D012867:Skin / Q000294:innervation*
chemical_list: D000889:Anti-Arrhythmia Agents; D004077:Digoxin