What is a P value? Does anyone can give a simple explanation? I am not using an easy explanation with my students and maybe some of you are developing something interesting during classes !
For example, comparing the mean weight of male (M) and female (F) fishes we have: Mean of M = 2,46kg (n = 59) and Mean of F = 2,51kg (n = 59). Using a t test, the result is: df = 116, t = 0,26 and P = 0,79. Searching in books I have found different definitions. The explanation for P = 0,79 could be..... 1 - the probability of Type I error. 2 - the probability of rejecting a correct null hypothesis. 3 - the probability of incorrectly rejecting the null hypothesis. 4 - the probability of rejecting a null hypothesis when in fact it is true. 5 - the chance of getting statistic as extreme or more extreme than this one 6 - the strength of evidence against an hypothesis 7 - the probability of the observed difference between groups (or a larger difference) occurs 8 - the probability of obtaining a result equal to or more extreme than what was actually observed. 9 - .... 10 - ... What is the best way to explain this P = 0,79 ??? Thanks for any hints !!! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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.ecomam.hpg.ig.com.br ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ "Tutto di noi � un angelo con un'ala e possiamo volare soltanto se ci abbracciamo" . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
