undocumented ANOVA error/warning?

*To*: mathgroup at smc.vnet.net*Subject*: [mg57282] undocumented ANOVA error/warning?*From*: Lee Newman <leenewm at umich.edu>*Date*: Mon, 23 May 2005 02:20:57 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I am using the ANOVA function on a data set I am currently analyzing. It has been working well, but for a particular factor in the data I received the following warning: in: ANOVA[data, CellMeans -> True, SignificanceLevel -> 0.05] out: "DesignedRegress::badfit: Warning: unable to find a fit that is better than the mean response". I know that the means are quite similar for this data the across the two levels of the factor, but otherwise the factor and dependent variable are identical to all other factors I have been analyzing. The factor is in True/False form and the dependent variable contains reals. The format of data is the same as I have been using for all other ANOVAs I've run, namely data=MapThread[{#1, #2} &, {factor, dependentvariable}]. Does anyone know what this warning means? Thanks, Lee