Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
re: st: Stumped...xtmixed and ANOVA F-stats not agreeing for balanced design
From
"Airey, David C" <[email protected]>
To
"[email protected]" <[email protected]>
Subject
re: st: Stumped...xtmixed and ANOVA F-stats not agreeing for balanced design
Date
Thu, 5 May 2011 08:04:25 -0500
.
> Dear all,
>
> Thanks for all the help in previous messages. This thoughtful user community makes learning all the more enjoyable, so thank you.
>
> Hope some of the experts out there can help me get passed a stumping issue, comparing xtmixed with ANOVA.
>
> I'm running a Within-Subject model with 2 factors (a, b). The F-stats produced by the two methods are not agreeing, despite having balanced data.
Some of the random effects look to be very small, indicating poor fit? So is the ANOVA well fit, and meeting the required assumptions? This may not be the case for repeated measures univariate ANOVA with regard to sphericity. It seems to me that ANOVA in Stata will spit out an answer when xtmixed will choke, when xtmixed should indeed choke. I think maybe we should qualify getting the same results between the two methods for well fit, balanced models? Anyway, tell us if you think both models are well fit.
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/