RE: Are parametric assumptions importat ?

[Wuensch, Karl L]

Lise advised "I tell my students that the ANOVA is not robust to violation of the equal variances assumption, but that it's a stupid statistic anyway.  All it can say is either, "These means are <may be nearly> equal," or "There's a difference somewhere among these means, but I can't tell you where it is."  I tell them to move along to a good MCP <procedure for making multiple comparisons, such as REGWQ> and don't worry about the ANOVA.  Most MCP's don't require a significant F anyway.  And if you have unequal n's, use Games-Howell's MCP to find where the differences are."   Excellent advice, copied to my students (so they don't hear it only from me).  Now if we could only get our colleagues to listen!  ;-)   +++++++++++++++++++++++++++++++++++++++++++++++++ Karl L. Wuensch, Department of Psychology, East Carolina University, Greenville NC  27858-4353 Voice:  252-328-4102     Fax:  252-328-6283 [EMAIL PROTECTED]  http://core.ecu.edu/psyc/wuenschk/klw.htm