Comparing the regression slopes of independent groups.
In this study, we explore the effects of non-normality and heteroscedasticity when testing the hypothesis that regression lines associated with two independent groups have the same slopes. Our results indicate that some recently proposed methods that allow heteroscedasticity and perform well in extant simulation studies do not perform well for the situation at hand. Two of the methods studied here are recommended for general use.
Ng
Marie
M
Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington 98121, USA. marieng@u.washington.edu
Wilcox
Rand R
RR
D000704:Analysis of Variance; D003198:Computer Simulation; D003625:Data Collection / Q000706:statistics & numerical data; D006801:Humans; D008432:Mathematical Computing; D015233:Models, Statistical; D011584:Psychology / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000706:statistics & numerical data*; D012044:Regression Analysis; D015203:Reproducibility of Results; D012942:Social Sciences / Q000706:statistics & numerical data*; D012984:Software