Dear Paul, Levene's test tests the null hypothesis that the variance are equal, so a small p-value suggests that they are not. Looking at your output, it seems odd that you have as many as 96 groups.
John -------------------------------- John Fox Department of Sociology McMaster University Hamilton, Ontario Canada L8S 4M4 905-525-9140x23604 http://socserv.mcmaster.ca/jfox -------------------------------- > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Paul Smith > Sent: Wednesday, August 02, 2006 5:02 PM > To: r-help@stat.math.ethz.ch > Subject: Re: [R] Syntax of Levene's test > > On 8/2/06, John Fox <[EMAIL PROTECTED]> wrote: > > The argument y is the response variable and group is a > factor defining > > groups (as ?levene.test says). If you have more than one > factor, then > > you can use interaction() to create from them a factor with levels > > given by the product set of the levels of the individual factors. > > Here's an example > > > > > library(car) > > > data(Moore) > > > attach(Moore) > > > levene.test(conformity, interaction(fcategory, partner.status)) > > Levene's Test for Homogeneity of Variance > > Df F value Pr(>F) > > group 5 1.4694 0.2219 > > 39 > > > levels(interaction(fcategory, partner.status)) > > [1] "high.high" "low.high" "medium.high" "high.low" > "low.low" > > [6] "medium.low" > > > levels(fcategory) > > [1] "high" "low" "medium" > > > levels(partner.status) > > [1] "high" "low" > > > > I'll add a couple of examples to the help page. > > Thanks, John. Now, I understand how to use levene.test. There > is only a question remaining: is the null hypothesis > corresponding to homogeneity of variances, i.e., should one > conclude that > > Levene's Test for Homogeneity of Variance > Df F value Pr(>F) > group 95 3.5919 < 2.2e-16 *** > 864 > > tell us that the hypothesis that the variances are equal is > (highly) significant? > > Paul > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.