Re: More on Repeated Measures

Posted by S Elgie on Nov 23, 2006; 2:01am
URL: http://spssx-discussion.165.s1.nabble.com/More-on-Repeated-Measures-tp1072284p1072290.html

Hi  Paul,

The design I am testing has eight measures at three time periods, and  I am
conducting a multivariate repeated meassures analysis. The design is
completely repeated with no between-subjects factor(s).   I do get
univariate results, but what is puzzling me is the two tables containing
multivariate tests (Pillais and so on), one labelled 'Multivariate Tests'
and the other 'Tests of Within-Subjects Effects.'

Thanks!

Susan

>From: "Swank, Paul R" <[hidden email]>
>Reply-To: "Swank, Paul R" <[hidden email]>
>To: [hidden email]
>Subject: Re: More on Repeated Measures
>Date: Wed, 22 Nov 2006 16:00:56 -0600
>
>The multivariate tests assume multiariate normality and homegenous
>variance covariance matrices across groups, the univariate repeated
>measures assumes homegeneity of variance covariance matrices, sphericity
>of the variance covariance matrix and normality of the residuals. The
>univariate repeated measures is typically mor sensisitve since the
>violation of sphericity tends to result in more significant results. The
>tests are different and do have different degress of freedom.
>
>
>Paul R. Swank, Ph.D.
>Professor, Developmental Pediatrics
>Director of Research,
>
>
>University of Texas Health Science Center at Houston
>
>-----Original Message-----
>From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of
>S Elgie
>Sent: Wednesday, November 22, 2006 2:39 PM
>To: [hidden email]
>Subject: More on Repeated Measures
>
>Thanks so much for all help received on repeated measures.  I am
>emboldened to ask a further question.  When one does a multivariate
>repeated measures analysis, there are two tables of multivariate
>results.  The first is labelled 'Multivariate Tests' and contains tests
>of the intercept and within subject factor.  (For now let's assume just
>one repeated factor).  The second table is labelled 'Tests of
>Within-Subjects Effects' and contains just the tests of the repeated
>factor.  I have not ever had the problem of these two tables giving
>substantially different answers, such as one significant and the other
>not.  But the numbers and degrees of freedom etc.
>are different and I have never been sure why and particularly not sure
>which one should be reported.
>
>Thanks again,
>
>Susan
>
>QQ Consulting
>Toronto Canada
>[hidden email]