Dear friends, How to choose between parametric and non parametric tests? Following any texbook we can find the idea of using histograms, curtosis, skewness and... tests like Shapiro-Wilk to test normality. In the case of homocedasticity, we can use one of the best for this task, the Levene test.
But..... how can we check the test assumptions using other tests with assumptions too? Any statistical test is a probability model and any model need some assumptions to be accepted! For example, does anyone know what are the assumptions of the Shapiro-Wilk and Levene tests? How to test them? I am a biologist teaching statistics and trying to teach more than formulas for my students, so... please help me with this discussion ! Voltolini ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Prof. J. C. VOLTOLINI Grupo de Estudos em Ecologia de Mamiferos (ECOMAM) Universidade de Taubate, Departamento de Biologia Praca Marcelino Monteiro 63, Bom Conselho. Taubate, SP. CEP 12030-010. BRASIL. Tel: 0XX12 - 2254165 (Lab. Zool.) ou 2254277 (Depto. Biol.) E-Mail: [EMAIL PROTECTED] http://www.mundobio.rg3.net/ http://www.sobresites.com/ecologia/institui.htm ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
