On Thu, 16 Feb 2006, Chris Lawrence wrote: > On 2/15/06, Taka Matzmoto <[EMAIL PROTECTED]> wrote: >> I have two bianry variables (X and Y) and one continuous variable (Z). >> >> I like to know, after controlling for the continuous variable, where one of >> the binary is significantly related to the other binary variable using >> logistic regression >> >> model <- glm(Y ~ X + Z, family=binomial) >> >> Is checking the significance of the coefficient of X a proper way for doing >> that ? > > Yes, that will do it.
Sorry, not so. That is a Wald test, and its power goes to zero as the true effect increases. You need to do a likelihood ratio test via anova() to get a reasonable test. Details in MASS (see the FAQ). -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
